640-822 Icnd1

Front 1

Which one of the following characteristics is true regarding the use of hubs and
switches?
A. Hubs can have their ports be configured with VLANs
B. Using hubs is costly with regard to bandwidth availability.
C. Switches can not forward broadcasts.
D. Switches are more efficient than hubs in processing frames.
E. Switches increase the number of collision domains in the network.

Back 1

E. Switches increase the number of collision domains in the network

Hint 1

Explanation: Switches increases the number of collisions domains in the network.
Switches that are configured with VLANs will reduce the size of the collision
domains by increasing the number of collision domains in a network, but making
them smaller than that of one big, flat network.
Incorrect Answers:
A. Switches are capable of VLAN configurations, but hubs are not.
B. Hubs are generally the least costly method possible to connect multiple devices
together in a network.
C. Switches forward broadcasts and multicasts, by default, to all ports within the same
VLAN. Only routers block all broadcast traffic by default.
D. Switches and hubs can be equally efficient in processing frames, in theory. In practice,
switches are generally more efficient as they usually have more CPU and memory
allocated to them, and are generally much more expensive than a simple hub.

Front 2

When comparing and contrasting the similarities and differences between bridges
and switches, which of the following are valid statements? Choose all the valid
answer choices)
A. Bridges are faster than switches because they have fewer ports.
B. A switch is a multiport bridge,
C. Bridges and switches learn MAC addresses by examining the source MAC address of
each frame received.
D. A bridge will forward a broadcast but a switch will not.
E. Bridges and switches increase the size of a collision domain.
F. None of the above statements are true

Back 2

Answer: B, C

Hint 2

Explanation:
Both bridges and switches build the bridge table by listening to incoming frames and
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640-822
examining the source MAC address in the frame.
Switches are multiport bridges that allow you to create multiple broadcast domains. Each
broadcast domain is like a distinct virtual bridge within a switch.
Incorrect Answers:
A. Switches are generally faster than bridges. Bridges also do not necessarily have fewer
ports than switches.
D. Both bridges and switches will forward broadcast and multicast traffic, assuming that
the traffic remains in the same VLAN.
E. The use of VLANs in a switch can decrease the size of the collision domain, by
creating additional, smaller collision domains

Front 3

Which of the following correctly describe the various functions and virtues of a
router? (Select all valid answer choices)
A. Packet switching
B. Collision prevention on a LAN segment.
C. Packet filtering
D. Broadcast domain enlargement
E. Broadcast forwarding
F. Internetwork communication
G. None of the above

Back 3

Answer: A, C, F

Hint 3

Explanation:
The main function of a router is to connect different, separated networks together. In
doing so, switching packets from one network to another is a primary function, along
with providing for communication between networks. As an additional feature, routers
are capable of providing filtering on a network address and application port level, so
choice C is also correct.
Incorrect Answers:
B. Routers can indeed be used to segment a network separate a collision domain, since
routers do not forward LAN broadcasts and multicasts to other interfaces. However,
routers alone can not prevent all collisions from occurring on any given LAN segment.
D. Routers actually segment LANs into smaller broadcast domains.
E. Routers do not forward broadcast and multicast traffic out the additional interfaces by
default. Unless bridging or IP helpers are configured on the router, LAN broadcasts are
blocked at the router level

Front 4

The LAN needs are expanding at the Certkiller corporate office, which is quickly
growing. You are instructed to enlarge the area covered by a single LAN segment on
the Certkiller network.
bridges that allow you to create multiple broadcast domains. Each
broadcast domain is like a distinct virtual bridge within a switch.
Which of the following are layer 1 devices that you can use? (Choose all that apply.)
A. A switch
B. A router
C. A network adapter card
D. A hub
E. A repeater

Back 4

Answer: D, E

Hint 4

Explanation:
A hub simply repeats the electrical signal and makes no attempt to interpret the electrical
signal (layer 1) as a LAN frame (Layer 2). So, a hub actually performs OSI layer 1
functions, repeating an electrical signal, whereas a switch performs OSI layer 2
functions, actually interpreting Ethernet header information, particularly addresses, to
make forwarding decisions. Hubs can be used to increase the number of stations that can
be supported on a LAN.
Because the repeater does not interpret what the bits mean, but does examine and
generate electrical signals, a repeater is considered to operate at Layer 1. Repeaters can
be used to physically extend the LAN to greater distances.

Front 5

Cisco is the leader in the router market space. What basic functions do their routers
perform in a network? (Choose two)
A. The microsegmentation of broadcast domains
B. Path selection
C. Packet switching
D. Bridging between LAN segments
E. Access layer security
F. VLAN membership assignment
G. Application optimization

Back 5

Answer: B, C

Hint 5

Explanation:
The primary functions of a router are: Packet Switching and Path Selection. It is the
routers job to determine the best method for delivering the data, and switching that data
as quickly as possible

Front 6

The Certkiller network administrator needs to determine what LAN devices to
install on the Certkiller network. What are two advantages of using Layer 2
Ethernet switches over hubs? (Choose two)
A. Allowing simultaneous frame transmissions
B. Increasing the size of broadcast domains
C. Increasing the maximum length of UTP cabling between devices
D. Filtering frames based on MAC addresses
E. Decreasing the number of collision domains

Back 6

Answer: A, D

Hint 6

Explanation:
A: A half duplex connection is where only one device can send or receive at a time. A
full duplex connection is where both devices can send and receive at the same time.
Thus, if you have a 100Mb half-duplex connection, only sending at 100Mb OR receiving
at 100Mb can happen at the same time. If you have a 100Mb full duplex connection, you
can effectively get 200Mb out of the link because you could be sending 100Mb and
receiving 100Mb at the same time.
D: Switches are capable of filtering frames based on any Layer 2 fields. For example, a
switch can be programmed to reject (not forward) all frames sourced from a particular
network. Because link layer information often includes a reference to an upper-layer
protocol, switches usually can filter on this parameter. Furthermore, filters can be helpful
in dealing with unnecessary broadcast and multicast packets.

Front 7

CDP is being used throughout the Certkiller network. What are two reasons why the
Certkiller network administrator would use CDP? (Choose two)
A. To determine the status of network services on a remote device
B. To obtain the IP Address of a connected device in order to telnet to the device
C. To verify the type of cable interconnecting two devices
D. To verify Layer 2 connectivity between two devices when Layer 3 fails
E. To obtain VLAN information from directly connected switches
F. To determine the status of the routing protocols between directly connected routers
G. To support automatic network failover during outages

Back 7

Answer: B, D

Hint 7

Explanation:
Cisco Discovery Protocol (CDP) is a proprietary protocol designed by Cisco to help
administrators collect information about both locally attached and remote devices. By
using CDP, you can gather hardware and protocol information about neighbor devices,
which is useful info for troubleshooting and documenting the network.
You can use:
Show cdp neighbor
Show cdp neighbor details
Commands to gather the information of connected neighbors

Front 8

CDP is running between two Certkiller devices. What information is supplied by
CDP? (Select three)
A. Device Identifiers
B. Capabilities list
C. Platform
D. Route identifier
E. Neighbor traffic data

Back 8

Answer: A, B, C

Front 9

Two Certkiller offices are connected as shown below:
Two buildings on the London campus of a the Certkiller corporation must be
connected to use Ethernet with a bandwidth of at least 100 Mbps. Certkiller is
concerned about possible problems from voltage potential differences between the
two buildings. Which media type should be used for the connection?
A. Coaxial cable
B. Fiber optic cable
C. UTP cable
D. STP cable

Back 9

E. None of the above

Hint 9

Current Ethernet technology typically comes via either copper UTP or fiber cables. In
this scenario the distance between the buildings is only 55 meters so either copper or
fiber could be used, as the distance limitation for 100M UTP Ethernet is 100 meters.
However, fiber would be a better fit as it is not prone to errors that could occur due to the
voltage potential differences. Because fiber is a dielectric material, it's not susceptible to
electrical interference. FO-product vendors also claim that fiber systems make secure
communications easier. Interference immunity and lack of emissions are givens in FO
systems and in the fiber medium itself.

Front 10

You work as a network technician at Certkiller .com. Please study the exhibit
carefully. Based on the information shown above, what is needed to allow host
Certkiller 1 to ping host Certkiller 2?

Back 10

Answer: E

Hint 10

Explanation:
Routers are Layers 3 devices used for inter-network communication. In this scenario
there are two different networks, so both switches need to connect to a router using
straight-through cables.
A straight-through cable is used to connect two different devices like, switch to router,
host to switch. Since we need to insert a router for communication between the two
switches, straight through cables will be used between the switches and the router

Front 11

A new Certkiller office is opening, and a network device needs to be installed in the
place of the icon labeled Network Device to accommodate a leased line T1 to the
Internet. Which network device and interface configuration meets the minimum
requirements for this installation?
A. A switch with two Ethernet interfaces
B. A router with two Ethernet interfaces
C. A switch with one Ethernet and one serial interface
D. A router with one Ethernet and one serial interface
E. A router with one Ethernet and one modem interface
F. None of the above

Back 11

Answer: D

Hint 11

Explanation:
Only a router can terminate a leased line T1 access circuit, and only a router can connect
two different IP networks. Here, we will need a router with two interfaces, one serial
connection for the T1 and one Ethernet interface to connect to the switch on the LAN

Front 12

As a CCNA candidate, you must know the various layers of the OSI model. At
which layers of the OSI Model do Wide Area Networks operate in? (Choose two)
A. Physical Layer
B. Datalink Layer
C. Network Layer
D. Session Layer
E. Transport Layer
F. Presentation Layer
G. Application Layer

Back 12

Answer: A, B

Hint 12

Explanation:
A WAN is a data communications network that covers a relatively broad geographic area
and that often uses transmission facilities provided by common carriers, such as
telephone companies. WAN technologies generally function at the lower two layers of
the OSI reference model: the physical layer and the data link layer as shown below.
Note:
Occasionally WAN's would also be considered to operate at layer 3, but since this
question asked for only 2 choices layers 1 and 2 are better choices

Front 13

While troubleshooting a connectivity problem on the network, you issue the ping
command from your PC command prompt, but the output shows "request times
out."
At which OSI layer is this problem associated with?
A. The data link layer
B. The application layer
C. The access layer
D. The session layer
E. The network layer

Back 13

Answer: E

Hint 13

Explanation:
TCP/IP includes ICMP, a protocol designed to help manage and control the operation of
a TCP/IP network. The ICMP protocol provides a wide variety of information about a
network's health and operational status. Control message is the most descriptive part of a
name. ICMP helps control and manage IP's work and therefore is considered part of
TCP/IP's network layer.
Reference:
CCNA Self-Study CCNA ICND exam certification Guide (Cisco Press, ISBN
1-58720-083-X) page 277

Front 14

You download a file from an FTP site on the Internet. What is the highest layer in the
OSI model used in this FTP operation?
A. Application
B. Presentation
C. Session
D. Transport
E. Internet
F. Data Link
G. Physical

Back 14

Answer: A

Hint 14

Explanation:
Layer 7 is the application layer, which is the highest layer in the OSI model. This layer
describes the use of end user applications, such as opening movie files (avi, mpeg, etc)
used Microsoft Office applications, using WWW browsers, using Telnet, and using FTP

Front 15

A host computer has been correctly configured with a static IP address, but the
default gateway is incorrectly set. Which layer of the OSI model will be first
affected by this configuration error?
A. Layer 1
B. Layer 2
C. Layer 3
D. Layer 4
E. Layer 5
F. Layer 6
E. Layer 7

Back 15

Answer: C

Hint 15

Explanation:
IP Addressing and IP routing resides on the OSI Network layer, which is layer 3.

Front 16

Which layer of the OSI reference model is responsible for ensuring reliable
end-to-end delivery of data?
A. Application
B. Presentation
C. Session
D. Transport
E. Network
F. Data-Link

Back 16

Answer: D

Hint 16

Explanation:
A key function of the transport layer is to provide connection services for the protocols
and applications that run at the levels above it. These can be categorized as either
connection-oriented services or connectionless services. Some protocol suites, such as
TCP/IP, provide both a connection-oriented and a connectionless transport layer
protocol, to suit the needs of different applications.
The transport layer is also the place in the layer stack where functions are normally
included to add features to end-to-end data transport. Where network layer protocols are
normally concerned with just "best effort" communications, where delivery is not
guaranteed. Transport layer protocols are given intelligence in the form of algorithms that
ensure that reliable and efficient communication between devices takes place. This
encompasses several related jobs, including lost transmission detection and handling, and
managing the rate at which data is sent to ensure that the receiving device is not
overwhelmed.
Transmission quality, meaning ensuring that transmissions are received as sent, is so
important that some networking references define the transport layer on the basis of
reliability and flow-control functions. However, not all transport layer protocols provide
these services. Just as a protocol suite may have a connection-oriented and a
connectionless transport layer protocol, it may also have one that provides reliability and
data management services, and one that does not. Again, this is the case with TCP/IP:
there is one main transport layer protocol; TCP, that includes reliability and flow control
features, and a second, UDP, that doesn't.

Front 17

At which OSI layer is a logical path created between two host systems named CK1
and CK2 on the Certkiller LAN?
A. Physical
B. Session
C. Data link
D. Transport
E. Network
F. Application
G. Presentation

Back 17

Answer: E

Hint 17

Explanation:
The Network layer (also called layer 3) manages device addressing, tracks the location of
devices on the network, and determines the best way to move data, which means that the
Network layer must transport traffic between devices that aren't locally attached. Routers
(layer 3 devices) are specified at the Network layer and provide the routing services
within an internetwork.

Front 18

Which OSI layer is associated with the following: The acknowledgement of
transmissions, sequencing, and flow control across a network?
A. Layer 2
B. Layer 3
C. Layer 4
D. Layer 5
E. Layer 6
F. Layer 7

Back 18

Answer: C

Hint 18

Explanation:
The Transport layer (Layer 4) defines several functions, including the choice of
protocols. The most important Layer 4 functions are error recovery and flow control. The
transport layer may provide for retransmission, i.e., error recovery, and may use flow
control to prevent unnecessary congestion by attempting to send data at a rate that the
network can accommodate, or it might not, depending on the choice of protocols.
Multiplexing of incoming data for different flows to applications on the same host is also
performed. Reordering of the incoming data stream when packets arrive out of order is
included. Examples include: TCP, UDP, and SPX

Front 19

Which OSI layer header contains the address of a destination host that is on another
network?
A. Application
B. Presentation
C. Session
D. Transport
E. Network
F. Data link
G. Physical

Back 19

Answer: E

Hint 19

Explanation:
Only network address contains this information. To transmit the packets the sender uses
network address and datalink address. But the layer 2 address represents just the address
of the next hop device on the way to the sender. It is changed on each hop. Network
address remains the same.

Front 20

Which of the following correctly describe steps in the OSI data encapsulation
process? (Choose two)
A. The presentation layer translates bits into voltages for transmission across the physical
link.
B. The transport layer divides a data stream into segments and adds reliability and flow
control information.
C. Packets are created when the network layer adds Layer 3 addresses and control
information to a segment.
D. The data link layer adds physical source and destination addresses and an FCS to the
segment.
E. Packets are created when the network layer encapsulates a frame with source and
destination host addresses and protocol-related control information

Back 20

Answer: B, C

Hint 20

Explanation:
The Transport Layer:
You can think of the transport layer of the OSI model as a boundary between the upper
and lower protocols. The transport layer provides a data transport service that shields the
upper layers from transport implementation issues such as the reliability of a connection.
The transport layer provides mechanisms for:
Segmenting upper layer application
The establishment, maintenance, and orderly termination of virtual circuits
information flow control and reliability via TCP
Transport fault detection and recovery
The Network Layer:
Layer three of the OSI model is the network layer.
The network layer creates and sends packets from source network to destination
network.
it provides consistent end-to-end packet delivery service and control information
it creates and uses layer3 addresses for use in path determination and to forward
packets.
Incorrect Answers:
A: This correctly describes the physical layer, not the presentation layer.
D: Although the data link layer adds physical (MAC) source and destination addresses, it
adds it to a frame, not a segment.
E: Packets are encapsulated, not frames.

Front 21

Which one of the following characteristics is true regarding the use of hubs and
switches? (choose 1)
A. Hubs can have their ports be configured with VLANs
B. Using hubs is costly with regard to bandwidth availability.
C. Switches can not forward broadcasts.
D. Switches are more efficient than hubs in processing frames.
E. Switches increase the number of collision domains in the network.

Back 21

E. Switches increase the number of collision domains in the network

Hint 21

Explanation: Switches increases the number of collisions domains in the network.
Switches that are configured with VLANs will reduce the size of the collision
domains by increasing the number of collision domains in a network, but making
them smaller than that of one big, flat network.
Incorrect Answers:
A. Switches are capable of VLAN configurations, but hubs are not.
B. Hubs are generally the least costly method possible to connect multiple devices
together in a network.
C. Switches forward broadcasts and multicasts, by default, to all ports within the same
VLAN. Only routers block all broadcast traffic by default.
D. Switches and hubs can be equally efficient in processing frames, in theory. In practice,
switches are generally more efficient as they usually have more CPU and memory
allocated to them, and are generally much more expensive than a simple hub.

Front 22

When comparing and contrasting the similarities and differences between bridges
and switches, which of the following are valid statements? Choose all the valid
answer choices)
A. Bridges are faster than switches because they have fewer ports.
B. A switch is a multiport bridge,
C. Bridges and switches learn MAC addresses by examining the source MAC address of
each frame received.
D. A bridge will forward a broadcast but a switch will not.
E. Bridges and switches increase the size of a collision domain.
F. None of the above statements are true

Back 22

Answer: B, C

Hint 22

Explanation:
Both bridges and switches build the bridge table by listening to incoming frames and
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640-822
examining the source MAC address in the frame.
Switches are multiport bridges that allow you to create multiple broadcast domains. Each
broadcast domain is like a distinct virtual bridge within a switch.
Incorrect Answers:
A. Switches are generally faster than bridges. Bridges also do not necessarily have fewer
ports than switches.
D. Both bridges and switches will forward broadcast and multicast traffic, assuming that
the traffic remains in the same VLAN.
E. The use of VLANs in a switch can decrease the size of the collision domain, by
creating additional, smaller collision domains

Front 23

Which of the following correctly describe the various functions and virtues of a
router? (Select all valid answer choices)
A. Packet switching
B. Collision prevention on a LAN segment.
C. Packet filtering
D. Broadcast domain enlargement
E. Broadcast forwarding
F. Internetwork communication
G. None of the above

Back 23

Answer: A, C, F

Hint 23

Explanation:
The main function of a router is to connect different, separated networks together. In
doing so, switching packets from one network to another is a primary function, along
with providing for communication between networks. As an additional feature, routers
are capable of providing filtering on a network address and application port level, so
choice C is also correct.
Incorrect Answers:
B. Routers can indeed be used to segment a network separate a collision domain, since
routers do not forward LAN broadcasts and multicasts to other interfaces. However,
routers alone can not prevent all collisions from occurring on any given LAN segment.
D. Routers actually segment LANs into smaller broadcast domains.
E. Routers do not forward broadcast and multicast traffic out the additional interfaces by
default. Unless bridging or IP helpers are configured on the router, LAN broadcasts are
blocked at the router level

Front 24

The LAN needs are expanding at the Certkiller corporate office, which is quickly
growing. You are instructed to enlarge the area covered by a single LAN segment on
the Certkiller network.
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bridges that allow you to create multiple broadcast domains. Each
broadcast domain is like a distinct virtual bridge within a switch.
Incorrect Answers:
A. Switches are generally f
640-822
Which of the following are layer 1 devices that you can use? (Choose all that apply.)
A. A switch
B. A router
C. A network adapter card
D. A hub
E. A repeater

Back 24

Answer: D, E

Hint 24

Explanation:
A hub simply repeats the electrical signal and makes no attempt to interpret the electrical
signal (layer 1) as a LAN frame (Layer 2). So, a hub actually performs OSI layer 1
functions, repeating an electrical signal, whereas a switch performs OSI layer 2
functions, actually interpreting Ethernet header information, particularly addresses, to
make forwarding decisions. Hubs can be used to increase the number of stations that can
be supported on a LAN.
Because the repeater does not interpret what the bits mean, but does examine and
generate electrical signals, a repeater is considered to operate at Layer 1. Repeaters can
be used to physically extend the LAN to greater distances.

Front 25

Cisco is the leader in the router market space. What basic functions do their routers
perform in a network? (Choose two)
A. The microsegmentation of broadcast domains
B. Path selection
C. Packet switching
D. Bridging between LAN segments
E. Access layer security
F. VLAN membership assignment
G. Application optimization

Back 25

Answer: B, C

Hint 25

Explanation:
The primary functions of a router are: Packet Switching and Path Selection. It is the
routers job to determine the best method for delivering the data, and switching that data
as quickly as possible

Front 26

The Certkiller network administrator needs to determine what LAN devices to
install on the Certkiller network. What are two advantages of using Layer 2
Ethernet switches over hubs? (Choose two)
A. Allowing simultaneous frame transmissions
B. Increasing the size of broadcast domains
C. Increasing the maximum length of UTP cabling between devices
D. Filtering frames based on MAC addresses
E. Decreasing the number of collision domains

Back 26

Answer: A, D

Hint 26

Explanation:
A: A half duplex connection is where only one device can send or receive at a time. A
full duplex connection is where both devices can send and receive at the same time.
Thus, if you have a 100Mb half-duplex connection, only sending at 100Mb OR receiving
at 100Mb can happen at the same time. If you have a 100Mb full duplex connection, you
can effectively get 200Mb out of the link because you could be sending 100Mb and
receiving 100Mb at the same time.
D: Switches are capable of filtering frames based on any Layer 2 fields. For example, a
switch can be programmed to reject (not forward) all frames sourced from a particular
network. Because link layer information often includes a reference to an upper-layer
protocol, switches usually can filter on this parameter. Furthermore, filters can be helpful
in dealing with unnecessary broadcast and multicast packets.

Front 27

CDP is being used throughout the Certkiller network. What are two reasons why the
Certkiller network administrator would use CDP? (Choose two)
A. To determine the status of network services on a remote device
B. To obtain the IP Address of a connected device in order to telnet to the device
C. To verify the type of cable interconnecting two devices
D. To verify Layer 2 connectivity between two devices when Layer 3 fails
E. To obtain VLAN information from directly connected switches
F. To determine the status of the routing protocols between directly connected routers
G. To support automatic network failover during outages

Back 27

Answer: B, D

Hint 27

Explanation:
Cisco Discovery Protocol (CDP) is a proprietary protocol designed by Cisco to help
administrators collect information about both locally attached and remote devices. By
using CDP, you can gather hardware and protocol information about neighbor devices,
which is useful info for troubleshooting and documenting the network.
You can use:
Show cdp neighbor
Show cdp neighbor details
Commands to gather the information of connected neighbors

Front 28

CDP is running between two Certkiller devices. What information is supplied by
CDP? (Select three)
A. Device Identifiers
B. Capabilities list
C. Platform
D. Route identifier
E. Neighbor traffic data

Back 28

Answer: A, B, C

Front 29

Two Certkiller offices are connected as shown below:
Two buildings on the London campus of a the Certkiller corporation must be
connected to use Ethernet with a bandwidth of at least 100 Mbps. Certkiller is
concerned about possible problems from voltage potential differences between the
two buildings. Which media type should be used for the connection?
A. Coaxial cable
B. Fiber optic cable
C. UTP cable
D. STP cable

Back 29

E. None of the above

Hint 29

Current Ethernet technology typically comes via either copper UTP or fiber cables. In
this scenario the distance between the buildings is only 55 meters so either copper or
fiber could be used, as the distance limitation for 100M UTP Ethernet is 100 meters.
However, fiber would be a better fit as it is not prone to errors that could occur due to the
voltage potential differences. Because fiber is a dielectric material, it's not susceptible to
electrical interference. FO-product vendors also claim that fiber systems make secure
communications easier. Interference immunity and lack of emissions are givens in FO
systems and in the fiber medium itself.

Front 30

You work as a network technician at Certkiller .com. Please study the exhibit
carefully. Based on the information shown above, what is needed to allow host
Certkiller 1 to ping host Certkiller 2?

Back 30

Answer: E

Hint 30

Explanation:
Routers are Layers 3 devices used for inter-network communication. In this scenario
there are two different networks, so both switches need to connect to a router using
straight-through cables.
A straight-through cable is used to connect two different devices like, switch to router,
host to switch. Since we need to insert a router for communication between the two
switches, straight through cables will be used between the switches and the router

Front 31

When files are transferred between a host and an FTP server, the data is divided
into smaller pieces for transmission. As these pieces arrive at the destination host,
they must be reassembled to reconstruct the original file. What provides for the
reassembly of these pieces into the correct order?
A. The sequence number in the TCP header
B. The Start Frame Delimiter in the 802.3 Preamble
C. The TTL in the IP header
D. The acknowledgement number in the segment header
E. The frame check sequence in the Ethernet frame trailer

Back 31

Answer: A

Hint 31

Explanation:
The Transport layer can provide reliable networking via acknowledgments, sequencing,
and flow control.
Acknowledgments Delivered segments are acknowledged to the sender. If they are not
acknowledged, the sender will retransmit.
* Sequencing Data segments are sequenced into their original order when they arrive at
the destination.
* Flow Control Provides buffer controls that prevent packet flooding to the destination
host. Buffers store bursts of data for processing when the transmission is complete.
Layer 4 protocols include the following:
* Transmission Control Protocol (TCP)
* User Datagram Protocol (UDP)
Sequenced Packet Exchange (SPX)A reliable communications protocol created by
Novell NetWare

Front 32

Network equipment supporting the use of flow control mechanisms has been
recently installed in the Certkiller network. What is the purpose of flow control in a
data network?
A. It ensures that data is retransmitted if an acknowledgment is not received.
B. It reassembles segments in the correct order on the destination device.
C. It provides a mechanism for the receiver to control the transmission speed
D. It regulates the size of each datagram segment.
E. All of the above are functions of flow control

Back 32

Answer: C

Hint 32

Explanation:
Flow control paces the transmission of data between a sending device and a receiving
device. Flow control ensures that the receiving device can absorb the data sent to it
before the sending device sends more. When the buffers on the receiving device are full,
a message is sent to the sending device to suspend transmission until the data in the
buffers has been processed.
Incorrect Answers:
A. Data retransmission mechanisms are not handled by control. They are most often
handled by transport layer protocols such as TCP.
B. This describes the reassembly portion of the segmentation and reassembly (SAR)
function of network equipment.
D. The maximum transmission unit (MTU) handles the regulation of maximum frame
sizes

Front 33

You need to describe the various types of flow control to your co-workers. Which of
the following are types of flow control that can be used in a network? (Choose three)
A. Congestion avoidance
B. Windowing
C. Cut-through
D. Buffering
E. Load Balancing
F. Fast Forward

Back 33

Answer: A, B, D

Front 34

Study the exhibit shown above. Host Certkiller A has established a connection with
the Certkiller II server attached to interface E0 of the Certkiller 2 router. Which of
the following statements describe the information contained in protocol data units
sent from Host Certkiller to Certkiller II? (Choose three)
A. The destination port number in a segment header will have a value of 80
B. The destination IP address of a packet will be the IP address of the E0 interface of the
Certkiller 1 router
C. The destination IP address of a packet will be the IP address of the network interface
of the Certkiller II server
D. The destination address of a frame will be the MAC address of the E0 interface of
Certkiller 1 router

Back 34

Answer: A, C, D

Front 35

Which protocol below uses TCP port 443 at layer 4?
A. HTML
B. HTTPS
C. TFTP
D. Telnet
E. SMTP
F. None of the above

Back 35

Answer: B

Hint 35

Explanation:
HTTPS is the secured version of the HTTP application, which normally uses 128 bit SSL
encryption to secure the information sent and received on a web page. An example is a
banking web site, or a trustworthy shopping web site that takes credit card information. It
is an application layer protocol which uses TCP port 443.
Incorrect Answers:
A. HTML is not a protocol
C. TFTP uses UDP port 69.
D. Telnet uses TCP port 23.
E. SMTP uses TCP port 25.

Front 36

As a CCNA candidate, you will be expected to know the OSI model very well.
Which of the following are associated with the application layer (layer 7) of the OSI
model? (Choose two)
A. TCP
B. Telnet
C. FTP
D. Ping
E. IP
F. UDP

Back 36

Answer: B, C

Hint 36

Explanation:
The application layer is the top layer of the OSI model and is used to describe the end
user applications that can be used over a network.
Layer Name Examples
Application (layer 7) Telnet, HTTP, FTP, WWW browsers, NFS, SMTP gateways,
SNMP
Incorrect Answers:
A. TCP resides at layer 4.
D. ARP is a function of the data link layer, which is layer 2.
E. IP is used at layer 3 (network layer).
Reference: CCNA Self-Study CCNA INTRO exam certification Guide (Cisco Press,
ISBN 1-58720-094-5) Page 34

Front 37

As the Certkiller network administrator, you are required to have a firm
understanding of the OSI model. Why does the data communication industry use
the layered OSI reference model? (Choose two)
A. It enables equipment from different vendors to use the same electronic components,
thus saving research and development funds
B. It encourages industry standardization by defining what functions occur at each layer
of the model
C. It divides the network communication process into smaller and simpler components;
thus aiding component development, design and troubleshooting
D. It provides a means by which changes in functionality in one layer require changes in
other layers
E. It supports the evolution of multiple competing standards and thus provides business
opportunities for equipment manufacturers

Back 37

Answer: B, C

Hint 37

Explanation:
The OSI (Open System Interconnection) reference model was created as a reference point
for communications devices. A layered approach is used to segment the entire
telecommunications process into a series of smaller steps.
A is correct because it encourages a level of standardization by encouraging that
functions be compared to known layers. D is also correct because it allows engineers to
focus on the development, refining, and perfection of simpler components

Front 38

Which of the protocols below use TCP at the transport layer? (Select four)
A. TFTP
B. SMTP
C. SNMP
D. FTP
E. HTTP
F. HTTPS

Back 38

Answer: B, D, E, F

Hint 38

Explanation:
SMTP (Simple Mail Transfer Profile for email), FTP (File Transfer Protocol), and
HTTP/HTTPS (Hyper Text Transfer Protocol for internet) all use TCP because of the
reliable delivery mechanism. SMTP uses TCP port 25, FTP uses TCP ports 20 and 21,
HTTP uses TCP port 80, and HTTPS uses TCP port 443.
Incorrect Answers:
A, C: SNMP and TFTP use UDP as the transport mechanism. Generally speaking,
protocols that use the keywords "trivial" or "simple" uses UDP, since connectionless,
best effort delivery mechanism usually suffice.
Reference: CCNA Self-Study CCNA INTRO exam certification Guide (Cisco Press,
ISBN 1-58720-094-5) Page 163.

Front 39

The exhibit above displays the partial contents of an encapsulation header.
Actualtests.com - The Power of Knowing

640-822
Which of the following are true of the network traffic represented in this diagram?
(Select three)
A. This is a UDP header
B. This is an OSI layer 4 header.
C. This is traffic from an FTP server.
D. This is traffic from an Telnet client.
E. The last PDU received in this session had a sequence number of 292735.

Back 39

Answer: B, C, E

Hint 39

Explanation:
As the header contains the sequence number and ACK number fields, it represents a TCP
header. Choice B is correct as TCP works on Layer 4 i.e. Transport Layer.
Source Port mentioned in the header is 21 which indicate it is FTP Traffic because FTP
uses port 20 and 21 for data and control. So choice C is correct.
The acknowledgment number refers to the sequence number of the last PDU received,
which is 292735, making choice E also correct.

Front 40

Acknowledgements, sequencing, and flow control are functions that are handled by
which layer of the OSI model?
A. Layer 5
B. Layer 4
C. Layer 7
D. Layer 6
E. Layer 3
F. Layer 2
G. Layer 1

Back 40

Answer: B

Front 41

A receiving host has failed to receive all of the segments that it should acknowledge.
What can the host do to improve the reliability of this communication session?
A. Start a new session using UDP
B. Obtain a new IP address from the DHCP server
C. Use a different source port for the session
D. Decrease the sequence number
E. Decrease the window size

Back 41

Answer: E

Hint 41

Explanation:
A TCP window the amount of outstanding (unacknowledged by the recipient) data a
sender can send on a particular connection before it gets an acknowledgment back from
the receiver that it has gotten some of it.
For example if a pair of hosts are talking over a TCP connection that has a TCP window
size of 64 KB (kilobytes), the sender can only send 64 KB of data and then it must stop
and wait for an acknowledgment from the receiver that some or all of the data has been
received. If the receiver acknowledges that all the data has been received then the sender
is free to send another 64 KB.
One way to improve the reliability of the TCP connection is to reduce the window size
that the receiver needs to receive before sending an acknowledgement. However, this will
reduce throughput as more segments and acknowledgements will need to be sent in order
to transfer the same amount of data

Front 42

You have set up an Internet based FTP server, where people can upload and
download files. In terms of the OSI model, what is the highest layer used during the
FTP sessions.
A. Application
B. Presentation
C. Session
D. Transport
E. Internet
F. Data Link
G. Physical

Back 42

Answer: A

Hint 42

Explanation:
The application layer is the highest layer (layer 7) of the OSI model, and is reserved for
end user applications. Since FTP is itself an application, layer 7 is the highest layer used.
Incorrect Answers:
B, C, D, E, F, G. In any given FTP session, all of these layers will be used at some point
but they are incorrect because the question asked for the highest layer used by FTP.

Front 43

Which Layer 4 protocol is used for a Telnet connection between two Certkiller
routers?
A. IP
B. ICMP
C. DNS
D. TCP
E. UDP
F. RTP

Back 43

Answer: D

Hint 43

Explanation:
TCP is a reliable connection-oriented protocol. TCP uses acknowledgments, sequencing,
and flow control to ensure reliability. Telnet uses TCP port 23

Front 44

DRAG DROP
You work as a network administrator at Certkiller .com.
Your boss, Mrs. Certkiller, is interested in the OSI layers. Match the terms with the
appropriate layer. Some options are not used

Back 44

Check PDF

Hint 44

Explanation:
The Transport layer segments and reassembles data into a data stream. Services located
in the Transport layer segment and reassemble data from upper-layer applications and
unite it into the same data stream. They provide end-to-end data transport services and
can establish a logical connection between the sending host and destination host on an
internetwork.
TCP and UDP transport protocol lies on Transport Layer, which break down the data
coming from upper layer into segment.
Windows are used to control the amount of outstanding, unacknowledged
data segments that is also on Transport Layer.
Network Layer:
The Network layer (also called layer 3) manages device addressing, tracks the location of
devices on the network, and determines the best way to move data, which means that the
Network layer must transport traffic between devices that aren't locally attached. Routers
(layer 3 devices) are specified at the Network layer and provide the routing services
within an internetwork.
Protocol Data Packets (PDU) on Network Layer is known as Packets. Routing and
Routed protocols are lies on Network Layer.
Routing Protocol: RIP, IGRP, EIGRP, OSPF, BGP
Routed Protocol: IP, IPX

Front 45

What data structure is described in the exhibit shown above?
A. IP datagram
B. TCP segment
C. Ethernet frame
D. UDP datagram
E. FDDI frame
F. Token Ring frame
G. None of the above

Back 45

Answer: B

Hint 45

Explanation:
The Figure below illustrates the fields and overall format of a TCP packet.
Twelve fields comprise a TCP packet
The following descriptions summarize the TCP packet fields illustrated above.
1. SourcePort and DestinationPort-Identifies points at which upper-layer source and
destination processes receive TCP services.
2.
3. Sequence Number-Usually specifies the number assigned to the first byte of data in the
current message. In the connection-establishment phase, this field also can be used to
identify an initial sequence number to be used in an upcoming transmission.
4.
5. Acknowledgment Number-Contains the sequence number of the next byte of data the
sender of the packet expects to receive.
6.
7. Data Offset-Indicates the number of 32-bit words in the TCP header.
8.
9. Reserved-Remains reserved for future use.
10.
11. Flags-Carries a
variety of control information, including the SYN and ACK bits used for connection
establishment, and the FIN bit used for connection termination.
12.
13. Window-Specifies the size of the sender's receive window (that is, the buffer space
available for incoming data).
14.
15. Checksum-Indicates whether the header was damaged in transit.
16.
17. Urgent Pointer-Points to the first urgent data byte in the packet.
18.
19. Options-Specifies various TCP options.
Data-Contains upper-layer information

Front 46

FTP, Telnet, DNS, and SMTP are all protocols being used in the Certkiller network.
Of these, which uses both TCP and UDP ports?
A. Telnet
B. FTP
C. DNS
D. SMTP
E. None of the above

Back 46

Answer: C

Hint 46

Explanation:
The following port numbers for the protocols listed above are as follows:
FTP: TCP Port 20 and 21
SMTP: TCP Port 25
Telnet: TCP Port 23
DNS: both TCP and UDP Port 53

Front 47

ICMP is often used in troubleshooting and verifying network. What statements are
true regarding ICMP packets? (Choose two)
A. They acknowledge receipt of TCP segments.
B. They guarantee datagram delivery.
C. They can provide hosts with information about network problems.
D. They are encapsulated within IP datagrams.
E. They are encapsulated within UDP datagrams.
F. They are encapsulated within TCP datagrams

Back 47

Answer: C, D

Hint 47

Explanation:
ping may be used to find out whether the local machines are connected to the network or
whether a remote site is reachable. This tool is a common network tool for determining
the network connectivity which uses ICMP protocol instead of TCP/IP and UDP/IP. This
protocol is usually associated with the network management tools which provide network
information to network administrators, such as ping and traceroute (the later also uses the
UDP/IP protocol).
ICMP is quite different from the TCP/IP and UDP/IP protocols. No source and
destination ports are included in its packets. Therefore, usual packet-filtering rules for
TCP/IP and UDP/IP are not applicable. Fortunately, a special "signature" known as the
packet's Message type is included for denoting the purposes of the ICMP packet. Most
commonly used message types are namely, 0, 3, 4, 5, 8, 11, and 12 which represent echo
reply, destination unreachable, source quench, redirect, echo request, time exceeded, and
parameter problem respectively.
In the ping service, after receiving the ICMP "echo request" packet from the source
location, the destination
Incorrect Answers
ICMP is an IP protocol so A and E are incorrect.
ICMP doesn't guarantee datagram delivery so B is wrong as well

Front 48

Although TCP segments are similar to UDP segments, TCP packets contains some
additional fields. Which of the following are found in a TCP header, but not in a
UDP header? (Choose three)
A. Checksum
B. Sequence number
C. Destination port
D. Window size
E. Acknowledgment number
F. Source port

Back 48

Answer: B, D, E

Hint 48

Explanation:
The Figure below illustrates the fields and overall format of a TCP packet
TCP Packet Field Descriptions
The following descriptions summarize the TCP packet fields illustrated in Figure 30-10:
1. Source Port and Destination Port-Identifies points at which upper-layer source and
destination processes receive TCP services.
2. Sequence Number-Usually specifies the number assigned to the first byte of data in the
current message. In the connection-establishment phase, this field also can be used to
identify an initial sequence number to be used in an upcoming transmission.
3. Acknowledgment Number-Contains the sequence number of the next byte of data the
sender of the packet expects to receive.
4. Data Offset-Indicates the number of 32-bit words in the TCP header.
5. Reserved-Remains reserved for future use.
6. Flags-Carries a variety of control information, including the SYN and ACK bits used
for connection establishment, and the FIN bit used for connection termination.
7. Window-Specifies the size of the sender's receive window (that is, the buffer space
available for incoming data).
8. Checksum-Indicates whether the header was damaged in transit.
9. Urgent Pointer-Points to the first urgent data byte in the packet.
10. Options-Specifies various TCP options.
11. Data-Contains upper-layer information.
User Datagram Protocol (UDP)
The User Datagram Protocol (UDP) is a connectionless transport-layer protocol (Layer 4)
that belongs to the Internet protocol family. UDP is basically an interface between IP and
upper-layer processes. UDP protocol ports distinguish multiple applications running on a
single device from one another.
Unlike the TCP, UDP adds no reliability, flow-control, or error-recovery functions to IP.
Because of UDP's simplicity, UDP headers contain fewer bytes and consume less
network overhead than TCP.
UDP is useful in situations where the reliability mechanisms of TCP are not necessary,
such as in cases where a higher-layer protocol might provide error and flow control.
UDP is the transport protocol for several well-known application-layer protocols,
including Network File System (NFS), Simple Network Management Protocol (SNMP),
Domain Name System (DNS), and Trivial File Transfer Protocol (TFTP).
packet format contains four fields, as shown in the figure below. These include
source and destination ports, length, and checksum fields.
A UDP packet consists of four fields.
Source and destination ports contain the 16-bit UDP protocol port numbers used to
demultiplex datagrams for receiving application-layer processes. A length field specifies
the length of the UDP header and data. Checksum provides an (optional) integrity check
on the UDP header and data.
Reference: http://www.cisco.com/univercd/cc/td/doc/cisintwk/ito_doc/ip.htm#xtocid21
The UDP

Front 49

DRAG DROP
You work as a network administrator at Certkiller .com.
Your boss, Mrs. Certkiller, is interested in the OSI layers. Match the items with the
appropriate layers. Note that not all options are used.

Back 49

Check PDF

Front 50

Certkiller is installing IP phones in a new office. The phones and office computers
connect to the same device. To ensure maximum throughout for the phone data
sessions, the company needs to make sure that the phone traffic is on a different
network from that of the office computer data traffic. What is the best network
device to which to directly connect the phones and computers and what technology
should be implemented on this device? (Choose two)
A. VLAN
B. Subinterface
C. STP
D. Hub
E. Switch
F. Router
G. Wireless Access Point
H. VTP

Back 50

Answer: A, E

Front 51

The corporate head office of Certkiller has a teleconferencing system that uses VOIP
(voice over IP) technology. This system uses UDP as the transport for the data
transmissions. If these UDP datagrams arrive at their destination out of sequence,
what will happen?
A. UDP will send an ICMP Information Request to the source host.
B. UDP will pass the information in the datagrams up to the next OSI layer in the order
that they arrive.
C. UDP will drop the datagrams.
D. UDP will use the sequence numbers in the datagram headers to reassemble the data in
the correct order.
E. UDP will not acknowledge the datagrams and wait for a retransmission of the
datagrams.

Back 51

Answer: B

Hint 51

Explanation:
VOIP systems utilize UDP because it is faster and uses less overhead. In addition, the
reliable transport mechanism used in TCP is useless to VOIP because if a packet gets
dropped and needs to be resent, it will be already too late.
UDP provides a service for applications to exchange messages. Unlike TCP, UDP is
connectionless and provides no reliability, no windowing, and no reordering of the
received data. However, UDP provides some functions of TCP , such as data transfer,
segmentation, and multiplexing using port numbers, and it does so with fewer bytes of
overhead and with less processing required. UDP data transfer differs from TCP data
transfer in that no reordering or recovery is accomplished. Applications that use UDP are
tolerant of lost data, or they have some application mechanism to recover data loss.
Reference: CCNA Self-Study CCNA INTRO exam certification Guide (Cisco Press,
ISBN 1-58720-094-5) Page 161.

Front 52

of the Certkiller network is shown below:
You work as a network technician for Certkiller and are responsible for this
network. Based on the diagram shown above, how many collision domains are
there?
A. Six
B. Fourteen
C. Four
D. Two
E. Three
F. One
G. Eight

Back 52

Answer: D

Hint 52

Explanation:
The multi-segment configuration guidelines apply only to a single Ethernet "collision
domain." A collision domain is formally defined as a single CSMA/CD network in which
there will be a collision if two computers attached to the system transmit at the same
time. An Ethernet system composed of a single segment or multiple segments linked with
repeaters is a network that functions as a single collision domain.
FIGURE 1 Repeater hubs create a single collision domain
The figure shows two repeater hubs connecting three computers. Since only repeater
connections are used between segments in this network, all of the segments and
computers are in the same collision domain.
In the next figure, the repeaters and DTEs are instead separated by a router (packet
switch) and are therefore in separate collision domains, since routers do not forward
collision signals from one segment to another. Routers contain multiple Ethernet
interfaces and are designed to receive a packet on one Ethernet port and transmit the data
onto another Ethernet port in a new packet.
FIGURE 2 Routers creates separate collision domains
Instead of propagating collision signals between Ethernet segments, routers interrupt the
collision domain and allow the Ethernets they link to operate independently. Therefore,
you can use packet switching hubs to build larger network systems by interconnecting
individual Ethernet systems

Front 53

You work as a network technician at Certkiller .com. You have been assigned the
task of designing a new Certkiller internetwork. The main priority is to achieve the
highest reliability available. Certkiller .com is willing to spend more dollars to avoid
downtime caused by link failure.
Which of the following four designs is to be preferred?
A. Design Certkiller A
B. Design Certkiller B
C. Design Certkiller C
D. Design Certkiller D

Back 53

Answer: A

Hint 53

Explanation:
A network topology that is set up so that each device is directly connected to every other
device on the network. This connection method has built-in redundancy. If one link goes
down, the device will transmit via another link.
Example: If the partial mesh design is a compromise between the network administrators
and managers, then the full mesh design implies that the network administrators won.
This design is every Cisco network administrator's picture of perfection over a Frame
Relay cloud. It gives every site a direct virtual circuit to every other site, as shown in
Figure This design gives maximum redundancy and minimum packet latency (latency
describes how long it takes a packet to reach each location)

Front 54

You work as a network technician at Certkiller .com. You have been assigned the
task of designing a new Certkiller internetwork. The main priority is the achieve the
highest reliability available, however not at all costs. Certkiller .com is willing to
spend more dollars to avoid downtime caused by link failure.
Which of the following four designs would provide some redundancy and increase
reliability for all four sites, but would cost less than a fully redundant topology?
A. Design Certkiller A
B. Design Certkiller B
C. Design Certkiller C
D. Design Certkiller D

Back 54

Answer: B

Hint 54

Explanation:
You can think of the partial mesh Frame Relay design as the compromise between
network administrators and cost-saving managers.
Example

Front 55

Explanation:
You can think of the partial mesh Frame Relay design as the compromise between
network administrators and cost-saving managers.
Example

Back 55

Answer: C

Hint 55

Explanation:
Every
network looks for cost efficiency. Redundancy is often sacrificed on the altar of monthly
cost. Thus, the hub and spoke Frame Relay network design is one of the more common.
In this configuration, you pick a centralized location (most likely, your largest, most
connected office) as the "hub" of the network. All other locations are considered
"spokes" and have a single virtual circuit connection back to the hub.
The major advantage of this configuration is the cost. It offers the cheapest monthly price
tag, which cost-cutting corporations enjoy. The disadvantages are beginning to mount
against this design, however. The redundancy is sorely lacking. If a single router (the
central router) loses connectivity for any reason (if the router crashes, if a trenching
company cuts through the line), your entire WAN goes down. The other disadvantage of
this design is beginning to eclipse even redundancy. It is the disadvantage of tandem
switching. Any time the spoke offices need to reach each other, they must go through the
hub office.

Front 56

Certkiller network is shown in the exhibit below:
The routers in this network are running RIPv2. Which addressing scheme would
satisfy the needs of this network yet waste the fewest addresses?
A. Network 1: 192.168.10.0/26Network 2: 192.168.10.64/26Network 3:
192.168.10.128/26Serial link 1: 192.168.20.0/24Serial link 2: 192.168.30.0/24
B. Network 1: 192.168.10.0/26Network 2: 192.168.10.64/28Network 3:
192.168.10.80/29Serial link 1: 192.168.10.88/30Serial link 2: 192.168.10.96/30
C. Network 1: 192.168.10.0/26Network 2: 192.168.10.64/27Network 3:
192.168.10.96/28Serial link 1: 192.168.10.112/30Serial link 2: 192.168.10.116/30
D. Network 1: 192.168.10.0/27Network 2: 192.168.10.64/28Network 3:
192.168.10.96/29Serial link 1: 192.168.10.112/30Serial link 2: 192.168.10.116/30

Back 56

Answer C

Hint 56

Explanation:
Network 1
Required Number of hosts :50
When We use the 26 bits for Network : 11111111.11111111.11111111.11000000 so 62
usable host can be in one network. 50 host for now and remaining hosts address for
further growth.
Network 2
Required Number of Hosts: 20
When we use the 27 bits for Network: 11111111.11111111.1111111.11100000 so 30
usable hosts can be in one network.
Network 3
Required Number of Hosts: 10
When we use the 28 bits for Network: 11111111.11111111.11111111.11110000 so 14
usable hosts can be in one network.
Connection between CK1 , CK2 and CK3 is WAN so when you use 30 bits network IP,
you will not lose any IP addresses from network since this subnet allows for only 2 host addresses.

Front 57

The Certkiller network is shown below:
A technician is investigating a problem with the network shown above. These
symptoms have been observed:
1. All of the user hosts can access the Internet.
2. None of the user hosts can access the server in VLAN9
3. All of the hosts can ping each other.
What could cause the symptoms?
A. Interface S0/0 on the router is down.
B. Interface Fa0/1 on the router is down.
C. Interface Fa0/5 on Certkiller 3 is down.
D. Interface Fa0/4 on Certkiller 3 is down.
E. Certkiller 2 is turned off.
F. Trunking is not enabled on the link between Certkiller 1 and Certkiller 3

Back 57

Answer: D

Hint 57

Explanation:
Since all user hosts have access to internet, link to router has to be up. Therefore, router
interface (Fa0/1 - believe it is labeled incorrectly on diagram as Fa1/0) must be up. Since
all hosts can ping each other, but none can get to VLAN 9 which is through single
interface Fa0/4, this interface must be down.
Choice A: incorrect, S0/0 must be up if internet access available.
Choice B: incorrect, Fa0/1 must be up if internet access (through router) available.
Choice C: incorrect, would not prevent access to VLAN9 via other routes (i.e. Fa0/7,
Fa0/9, Fa0/4)
Choice D: correct
Choice E: incorrect: Certkiller 2 must be up if internet access (through switch and then
router) available
Choice F: incorrect: Disabled trunking on link between Certkiller 1 and Certkiller 3 would
not prevent access to VLAN9 via other routes

Front 58

to the graphic shown below:
What symbol represents a type of device that is connected to interface FastEthernet
0/23 of the 2960 switch Sw1-2960?
A. Picture A
B. Picture B
C. Picture C
D. Picture D

Back 58

Answer: D

Hint 58

Some of the common Cisco symbols are shown below
Note: Choice B in this question represents an ATM switch, which is not pictured above.
From the output shown in this question, we can see that there a numerous different MAC
addresses associated with port Fa 0/23. This can only mean that a device with multiple
hosts attached to it is plugged into this port, such as a hub or another switch.

Front 59

Host Certkiller A pings Host Certkiller B, which entry will be in the ARP cache of
Host Certkiller A to support this transmission?
A. A
B. B
C. C
D. D
E. E

Back 59

C - See pdf

Front 60

Certkiller uses EIGRP as the routing protocol. Based on the info shown above, what
path will packets take from a host on the 192.168.10.192/26 network to a host on the
LAN attached to router Certkiller 1?
A. The path of the packets will be Certkiller 3 to Certkiller 2 to Certkiller 1
B. The path of the packets will be Certkiller 3 to Certkiller 1 to Certkiller 2
C. The path of the packets will be both Certkiller 3 to Certkiller 2 to Certkiller 1
AND Certkiller 3 to Certkiller 1
D. The path of the packets will be Certkiller 3 to Certkiller 1
E. None of the above

Back 60

Answer: D

Hint 60

Explanation:
Based on the routing table of Certkiller 3, the best path to the Certkiller 1 LAN is shown on
the first routing entry (192.168.10.64). Certkiller 3 will use the Serial 0/0 interface to
route traffic to this destination, with the next hop IP address of 192.168.10.9, which is the
network used between Certkiller 3 and Certkiller 1, making choice D correct. Note that
there is only one routing entry for this destination. If traffic were load balancing over
both paths, then both would be displayed in the routing table.

Front 61

Based on the diagram shown above, what is the correct addressing for a frame and
packet received by Host Certkiller B from Host Certkiller A?
A. Destination MAC: 0011.43da.2c98
Source MAC: 0070.0e8f.088a
Destination IP: 192.168.60.5
Source IP: 192.168.60.1
B. Destination MAC: 0011.43da.2c98
Source MAC: 0070.0e8f.088a
Destination IP: 192.168.60.5
Source IP: 192.168.24.5
C. Destination MAC: 0011.43da.2c98
Source MAC: 00b0.d0ef.5f6a
Destination IP: 192.168.60.5
Source IP: 192.168.24.5
D. Destination MAC: 0011.43da.2c98
Source MAC: 0070.0e97.af4e
Destination IP: 192.168.60.5
Source IP: 192.168.60.2
E. None of the above

Back 61

Answer: B

Hint 61

Explanation:
When packets leave from the host, the packets contains the source MAC and IP of the
host address. The source and destination IP address will not change. Because the host
knows that the destination is on another subnet, it will forward the packet to the default
gateway device, so the destination MAC address will be of the default gateway, which is
the FA0/0 interface of router Certkiller 3

Front 62

Please study the two exhibits carefully.
The partial frame shown above displays select header information as it arrives at
the destination host. Of the following choices shown below, which one represents the
correct header information in the responding frame returned to the remote host?
A. A
B. B
C. C
D. D
E. E

Back 62

Answer: A

Front 63

Based on the diagram above, which destination addresses will Host A use to send
data to Host B? (Choose two.)
A. The IP address of Certkiller 1
B. The IP address of Certkiller A Fa0/0
C. The IP address of Host B
D. The MAC address of Certkiller 1
E. The MAC address of Certkiller A Fa0/0
F. The MAC address of Host B

Back 63

Answer: C, E

Hint 63

Explanation:
When sending data from one host to another, destination information will be added to
every packet's header. The destination information will be the IP and MAC Address of
destination host. If the destination is found outside the subnet the MAC address of the
router is used. Note: The destination IP address will never change, unless NAT is
involved.

Front 64

Which IOS user EXEC command will allow a network technician to determine
which router in the path to an unreachable network host should be examined more
closely for the cause of the network failure?
A. Certkiller B> telnet
B. Certkiller B > ping
C. Certkiller B > trace
D. Certkiller B > show ip route
E. Certkiller B > show interface
F. Certkiller B > show cdp neighbors

Back 64

Answer: C

Hint 64

Explanation:
This can perform the trace command. It sends the ping packets to each of the routers on
the way to the receiver. The router which doesn't respond will be a potential failure place
in this network.

Front 65

Certkiller office's network topology is shown in the diagram below:
Host Certkiller A needs to communications with the e-mail server shown above.
What address will be placed on the destination address field of the frame when it
leaves host Certkiller A?
A. The MAC address of Certkiller A
B. The MAC address of switch Certkiller 1
C. The MAC address of the E0 interface of the Certkiller 3 router.
D. The MAC address of the E1 interface of the Certkiller 3 router.
E. The MAC address of switch Certkiller 2
F. The MAC address of the email server

Back 65

Answer: C

Hint 65

Explanation:
If the destination host is in the remote segment than the router will change the MAC
address of the source to its own. The inverse ARP protocol is by default on. Remember
that IP address is not changed after forwarding. The MAC address is changed after
crossing each broadcast domain

Front 66

You work as a network engineer at Certkiller .com. The topology of the
Certkiller .com network is displayed in the exhibit. Host Certkiller 1 has established a
connection with the HTTP server attached to interface E0 of the Certkiller B router.
Which of the following statements describe the information contained in protocol
data units sent from host Certkiller 1 to this server? (Select three)
A. The destination port number in a segment header will have a value of 80.
B. The destination port number in a segment header will have a unique value greater than
or equal to 1023.
C. The destination address of a frame will be the MAC address of the HTTP server
interface.
D. The destination address of a frame will be the MAC address of the E0 interface of the
Certkiller A router.
E. The destination IP address of a packet will be the IP address of the E0 interface of the
Certkiller A router.
F. The destination address of a packet will be the IP address of the HTTP-Server

Back 66

Answer: A, D, F

Hint 66

Explanation:
HTTP uses TCP port 80, making choice A correct. The source port will be chosen
randomly, but not the destination TCP port. The destination IP address will be left
unchanged, and since HTTP server is on a remote network, the destination MAC address
will be the MAC address of the default gateway ( E0 on Certkiller A).

Front 67

In this network, host Certkiller 1 is able to send data to Host Certkiller 2. How will
Router Certkiller D handle the data frame received from Host Certkiller 1? (Choose
three)
A. Router Certkiller D will strip off the source MAC address and replace it with the MAC
address on the forwarding Fast Ethernet interface
B. Router Certkiller D will strip off the source IP address and replace it with the IP
address on the forwarding Fast Ethernet interface
C. Router Certkiller D will strip off the destination MAC address and replace it with the
MAC address of Host Certkiller 2
D. Router Certkiller D will strip off the destination IP address and replace it with the IP
address of Host B
E. Router Certkiller D will forward the data frame out interface Fast Ethernet0/1
F. Router Certkiller D will forward the data frame out interface FastEthernet0/2

Back 67

Answer: A, C, F

Hint 67

Explanation:
Whereas switches can only examine and forward packets based on the contents of the
MAC header, routers can look further into the packet to discover the network for which a
packet is destined. Routers make forwarding decisions based on the packet's
network-layer header (such as an IPX header or IP header). These network-layer headers
contain source and destination network addresses.
Local devices address packets to the router's MAC address in the MAC header. After
receiving the packets, the router must perform the following steps
1. Check the incoming packet for corruption, and remove the MAC header . The
router checks the packet for MAC-layer errors. The router then strips off the MAC
header and examines the network-layer header to determine what to do with the packet.
2. Examine the age of the packet. The router must ensure that the packet has not come
too far to be forwarded. For example, IPX headers contain a hop count. By default, 15
hops is the maximum number of hops (or routers) that a packet can cross. If a packet has
a hop count of 15, the router discards the packet.
IP headers contain a Time to Live (TTL) value. Unlike the IPX hop count, which
increments as the packet is forwarded through each router, the IP TTL value decrements
as the IP packet is forwarded through each router. If an IP packet has a TTL value of 1,
the router discards the packet. A router cannot decrement the TTL value to 1 and then
forward the packet.
3. Determine the route to the destination. Routers maintain a routing table that lists
available networks, the direction to the desired network (the outgoing interface number),
and the distance to those networks. After determining which direction to forward the
packet, the router must build a new header. (If you want to read the IP routing tables on a
Windows 95/98 workstation, type ROUTE PRINT in the DOS box.)
4. Build the new MAC header and forward the packet.
Finally, the router builds a new MAC header for the packet. The MAC header includes
the router's MAC address and the final destination's MAC address or the MAC address of
the next router in the path.
Figure 5 shows the contents of a packet before and after it has been forwarded by a
router. Figure 5 also shows the contents of the router's routing tables.

Front 68

Refer to the exhibit above. Host A is communicating with host B. How will the data
be addressed when it leaves host A?
A. Source MAC=000A.8A47.E612
Destination MAC=000B.DC04.12F4
Source IP=192.168.23.4
Destination IP=192.168.23.1
B. Source MAC=000A.8A47.E612
Destination MAC=0010.7BE7.FAEF
Source IP=192.168.23.4
Destination IP=192.168.127.7
C. Source MAC=000A.8A47.E612
Destination MAC=000B.DC04.12F4
Source IP=192.168.23.4
Destination IP=192.168.127.7
D. Source MAC=000A.8A47.E612
Destination MAC=0010.7BE7.FAEF
Source IP=192.168.23.4
Destination IP=192.168.23.1
E. None of the above

Back 68

Answer: B

Hint 68

Explanation:
When packets leave from the host, the packets contains the source MAC and IP of the
host address. The source and destination IP address will not change (if it did, the router
devices would not know where to send the data). Because the host knows that the
destination is on another subnet, it will forward the packet to the default gateway device,
so the destination MAC address will be of the default gateway, which is the LAN
interface of router Certkiller 1

Front 69

Please study the exhibit above carefully. If host Certkiller A sends an IP packet to
host Certkiller B, what will the OSI Layer 3 source address be in the packet when it
reaches host B?
A. B2:B2:B2:B2:B2:B2
B. A1:A1:A1:A1:A1:A1
C. 10.168.10.99
D. 10.168.11.65
E. C3:C3:C3:C3:C3:C3
F. 10.168.11.88
G. None of the above

Back 69

Answer: C

Hint 69

Explanation:
When packets transfer from one host to another across a routed segment, the source IP
address always remains the same source IP address, and the physical (MAC) address will
be the existing router's interface address. Similarly, the destination IP address always
remains the same and the destination physical (MAC) address is the destination router's
interface address.

Front 70

Please study the exhibit carefully. If host Certkiller A sends an IP packet to host
Certkiller B, what will the source physical (MAC) address be in the frame when it
reaches host Certkiller B?
A. A1:A1:A1:A1:A1:A1
B. D4:D4:D4:D4:D4:D4
C. B2:B2:B2:B2:B2:B2
D. 10.168.11.88
E. 10.168.10.99
F. C3:C3:C3:C3:C3:C3

Back 70

Answer: F

Hint 70

Explanation:
When packets transfer from one host to another across a routed segment, the source IP
address always remains the same source IP address, and the source physical (MAC)
address will be the existing router's interface address. Similarly, the destination IP
address always remains the same and the destination physical (MAC) address is the
destination router's interface address.

Front 71

In the network below, host Certkiller A is transferring a file to the FTP server. Point
A represents the frame as it goes toward the Certkiller 1 router. What will the Layer
2 destination address be at this point?
A. 192.168.7.17
B. abcd.1123.0045
C. aabb.555.2222
D. 192.168.1.1
E. abcd.2246.0035

Back 71

Answer: E

Hint 71

Explanation:
For packets destined to a host on another IP network, the destination MAC address will
be the LAN interface of the router. Since the FTP server lies on a different network, the
host will know to send the frame to it's default gateway, which is Certkiller 1.

Front 72

Host Certkiller 1 needs to communicate with the email server shown above. What
address will be placed in the destination address field of the frame when it leaves
Host Certkiller 1?
A. The MAC address of Host Certkiller 1
B. The MAC address of E0 of the router Certkiller C
C. The MAC address of Switch Certkiller B
D. The MAC address of E1 of the router Certkiller C
E. The MAC address of Switch Certkiller A
F. The MAC address of the email server Certkiller D
G. None of the above

Back 72

Answer: B

Hint 72

Explanation:
Since the email server resides on a different IP subnet than the host Certkiller 1, the host
will send the frame to its default gateway. In this case, the router Certkiller C is acting as
the default gateway for all hosts on the LAN, so the frame will be sent to its Ethernet
interface so that it can be routed to the email server

Front 73

In this Certkiller network segment, host Certkiller A needs to send data to Host
Certkiller B. Which Layer 2 and Layer 3 destination addresses will be used in this
session to send the data from Host Certkiller A to Host Certkiller B?
A. 192.168.60.5 and 0007.0e56.ab2e
B. 192.168.24.2 and 0007.0e84.acef
C. 192.168.24.1 and 0007.0e56.ab2e
D. 192.168.60.5 and 0011.43da.2c98
E. None of the above

Back 73

Answer: A

Hint 73

Explanation:
When packets leave from the host, the packets contains the source MAC and IP of the
host address. The source and destination IP address will not change. Because the host
knows that the destination is on another subnet, it will forward the packet to the default
gateway device, so the destination MAC address will be of the default gateway, which is
the FA0/0 interface of router Certkiller 2.

Front 74

In this network segment, host Certkiller A sends data to Host Certkiller B. As packets
travel from host Certkiller A to host Certkiller B, which three devices will use the
destination MAC address of the packet to determine a forwarding path? (Choose
three)
A. Hub Certkiller 0
B. Switch Certkiller 1
C. Router Certkiller 5
D. Router Certkiller 4
E. Switch Certkiller 2
F. Switch Certkiller 3

Back 74

Answer: B, E, F

Hint 74

1. MAC address learning by a switch or a bridge is accomplished by the same method.
The switch or bridge listens to each device connected to each of its ports and scan the
incoming frame for the source MAC address. This creates a MAC address to port map
that is cataloged in the switches/bridge MAC database. Another name for the MAC
address table is content addressable memory or
CAM table.
2. When a switch or bridge is listening o the network traffic, it receives each frame and
compares it to the MAC address table. By checking the MAC table the switch/ bridge are
able o determine which port the frame came in on. If the frame is on the MAC table the
frame is filtered or transmitted on only that port. If the switch determines that the frame
is not on the MAC table, the frame is forwarded out to all ports except the incoming port

Front 75

You are logged into a router and wish to view the layer 3 information about your
neighboring Cisco routers. What IOS command gives layer 3 information for of the
directly connected router interfaces?
A. show ip links
B. show cdp neighbor
C. show cdp neighbor detail
D. show ip clients
E. show ip route
F. None of the above

Back 75

Answer: C

Hint 75

Explanation:
To display detailed information about neighboring devices discovered using Cisco
Discovery Protocol (CDP), use the show cdp neighbors privileged EXEC command.
Detail - (Optional) Displays detailed information about a neighbor (or neighbors)
including network address, enabled protocols, hold time, and software version.
Incorrect Answers:
A, D. These are invalid commands.
B. The "show cdp neighbor" command, without the "detail" keyword will not display the
additional layer 3 protocol information.
E. This will show all routes from all other routers within the domain. We wish to see
information from just the direct interface neighbors

Front 76

A Certkiller technician is troubleshooting connectivity problems between two
routers that are directly connected through the serial line. The technician notices
that the serial line is up but cannot see any neighbors displayed in the output of the
show cdp neighbors command.
In which OSI layer is the problem most likely occurring?
A. Physical
B. Data link
C. Network layer
D. Transport layer
E. Application layer

Back 76

Answer: B

Hint 76

Explanation:
As the question states that serial line is up, it means the problem is not on the Network
layer. The administrator cannot see any output by issuing the show cdp neighbors
command. It means that CDP is disabled and CDP is a protocol that runs over Layer2
(the data link layer) on all Cisco routers, bridges, access servers, and switches

Front 77

While troubleshooting a network connectivity problem, a Certkiller technician
observes steady link lights on both the workstation NIC and the switch port to
which the workstation is connected. However, when the ping command is issued
from the workstation, the output message "Request timed out." is displayed. At
which layer of the 7-layer OSI model does the problem most likely exist?
A. The data link layer
B. The application layer
C. The protocol layer
D. The access layer
E. The session layer
F. The network layer
G. None of the above

Back 77

Answer: F

Hint 77

Explanation:
Network Layer:
The Network layer (also called layer 3) manages device addressing, tracks the location of
devices on the network, and determines the best way to move data, which means that the
Network layer must transport traffic between devices that aren't locally attached. Routers
(layer 3 devices) are specified at the Network layer and provide the routing services
within an internetwork.
Request Time out, Destination Unreachable etc error comes from Network Layer
problem.

Front 78

Which line from the output of the show ip interface command indicates that there is
a Layer 1 problem?
A. Serial0/1 is up, line protocol is down
B. Serial0/1 is down, line protocol is down
C. Serial0/1 is up, line protocol is up
D. Serial0/1 is administratively down, line protocol is down
E. None of the above

Back 78

Answer: B

Hint 78

:
When the physical interface itself is down, then the problem is related to layer 1. When it
is up, but the line protocol is down, then the problem is related to layer 2.

Front 79

At which layer of the OSI model does the protocol that provides the information
displayed by the "show cdp neighbors" command operate?
A. Transport
B. Physical
C. Application
D. Data link
E. Network

Back 79

Answer: D

Hint 79

Explanation:
CDP is a device discovery protocol that runs over Layer 2 (the data link layer) on all
Cisco-manufactured devices (routers, bridges, access servers, and switches) and allows
network management applications to discover Cisco devices that are neighbors of already
known devices. With CDP, network management applications can learn the device type
and the Simple Network Management Protocol (SNMP) agent address of neighboring
devices running lower-layer, transparent protocols

Front 80

Which three of the protocols below belong to the application layer? (Select three
answer choices)
A. ARP
B. HTTPS
C. SMTP
D. CDP
E. TFTP
F. ICMP

Back 80

Answer: B, C, E

Hint 80

Explanation:
The application layer is the highest OSI layer, and protocols at this layer are end-user
oriented. HTTPS so people can get information on the internet, SMTP so people can
manage networks, and TFTP so people can download files.
Incorrect Answers:
A, D, F. ARP, CDP, ICMP are protocols that equipment like routers and switches use to
communicate with themselves, and belong to lower levels on the model.

Front 81

You want to upgrade the Certkiller LAN so that all ports operate in full duplex
mode. Which statement is true about full-duplex Ethernet when comparing to
half-duplex Ethernet?
A. Full-duplex Ethernet consists of a shared cable segment. Half-duplex provides a
point-to-point link
B. Full-duplex Ethernet uses two wires to send and receive. Half-duplex Ethernet uses
one wire to send and receive
C. Full-duplex Ethernet can provide higher throughput than can half-duplex Ethernet of
the same bandwidth
D. Full-duplex Ethernet uses a loopback circuit to detect collisions. Half-duplex Ethernet
uses a jam signal
E. None of the above

Back 81

Answer: C

Hint 81

Explanation:
Full-duplex Ethernet uses two pairs of wires instead of one wire pair like half duplex.
And full duplex uses a point-to-point connection between the transmitter of the
transmitting device and the receiver of the receiving device. This means that with
full-duplex data transfer, you get a faster data transfer compared to half duplex.

Front 82

What are two characteristics of "store and forward" switching? (Select two answer
choices)
A. Latency fluctuates regardless of frame size.
B. The switch receives the complete frame before beginning to forward it.
C. Latency through the switch varies with frame length.
D. The switch checks the destination address upon receipt of headers

Back 82

Answer: B, C

Hint 82

Explanation:
With store-and-forward, the entire frame is received by the switch before the first bit of
the frame is forwarded.
As soon as the incoming switch port receives enough of the frame to see the destination
MAC address, the forwarding decision is made and the frame is transmitted out the
appropriate outgoing port to the destination device. So, each frame might experience
slightly less latency. Store and forward switching may add latency when compared to
other switching methods such as cut through, but it can reduce the amount of errors that
become forwarded through a network.

Front 83

Split horizon has been enabled within the Certkiller routed network. Which one of
the following statements best explains the split horizon rule?
A. Only routers can split boundaries (horizons) between networks in separate AS
numbers.
B. Each AS must keep routing tables converged to prevent dead routes from being
advertised across boundaries.
C. Once a route is received on an interface, advertise that route as unreachable back out
the same interface.
D. Information about a route should never be sent back in the direction from which the
original update came.
E. None of the above

Back 83

Answer: D

Hint 83

Explanation:
The split horizon rule states:
* Never advertise a route out of the interface through which you learned it.
For instance, in Figure 4a below, if Router One is connected to Routers Two and Three
through a single multipoint interface (such as Frame Relay), and Router One learned
about Network A from Router Two, it will not advertise the route to Network A back out
the same interface to Router Three. Router one assumes that Router Three would learn
about Network A directly from Router Two.

Front 84

Which of the following commands would be applied to a WAN interface, but not on
LAN Interface? (Choose all that apply)
A. IP address
B. encapsulation PPP
C. no shutdown
D. authentication CHAP
E. Speed
F. None of the above

Back 84

Answer: B, D

Hint 84

Explanation:
PPP encapsulation can be used in ISDN interfaces, Asynchronous serial interfaces, and
point to point serial WAN connections. PPP is not an option for LAN interfaces. CHAP
authentication is a PPP 3 way authentication method. CHAP authentication can only be
used on PPP encapsulated interfaces and is not a LAN interface configuration option.
Incorrect Answers:
A, C. This command can be applied to both LAN and WAN interface types.
E. The speed command is used on LAN interfaces, and is not used on WAN interface
types

Front 85

What kind of cable should be used to establish a trunked line between two Catalyst
switches?
A. A straight-through cable
B. An EIA/TIA-232 serial cable
C. An auxiliary cable
D. A modem cable
E. A cross-over cable

Back 85

Answer: E

Hint 85

Explanation:
A crossover cable is used to connect two of the same device types, or devices from the
same OSI layer.

Front 86

Assuming you build networks to exact specifications, what is the recommended
maximum length a 10BaseT cable can be before it has to be segmented or repeated?
A. 100 meters
B. 100 feet
C. 100 yards
D. 200 meters
E. None of the above

Back 86

Answer: A

Hint 86

Explanation:
The distance standards are in meters and 10BaseT has a distance restriction of 100
meters. If you go further then that, you compromise data integrity. 10BastT is the
predominant cable type used in Ethernet networks

Front 87

The Certkiller LAN is upgrading all devices to operate in full duplex. Which
statement is true about full-duplex Ethernet in comparison to half-duplex Ethernet?
A. Full-duplex Ethernet uses two wires to send and receive. Half-duplex Ethernet uses
one wire to send and receive
B. Full-duplex Ethernet consists of a shared cable segment. Half-duplex Ethernet
provides a point-to-point link
C. Full-duplex Ethernet can provide higher throughout than can half-duplex Ethernet of
the same bandwidth
D. Full-duplex Ethernet uses a loopback circuit to detect collisions. Half-duplex ethernet
uses a jam signal
E. None of the above

Back 87

Answer: C

Front 88

A network administrator wants to control which user hosts can access the network
based on their MAC address. What will prevent workstations with unauthorized
MAC addresses from connecting to the network through a switch?
A. BPDU
B. Port security
C. RSTP
D. STP
E. VTP
F. Blocking mode

Back 88

Answer: B

Hint 88

Explanation:
UnderstandingHow PortSecurity Works
You can use port security to block input to an Ethernet, Fast Ethernet, or Gigabit Ethernet
port when the MAC address of the station attempting to access the port is different from
any of the MAC addresses specified for that port. Alternatively, you can use port security
to filter traffic destined to or received from a specific host based on the host MAC
address.
When a secure port receives a packet, the source MAC address of the packet is compared
to the list of secure source addresses that were manually configured or autoconfigured
(learned) on the port. If a MAC address of a device attached to the port differs from the
list of secure addresses, the port either shuts down permanently (default mode), shuts
down for the time you have specified, or drops incoming packets from the insecure host.
The port's behavior depends on how you configure it to respond to a security violation.
If a security violation occurs, the Link LED for that port turns orange, and a link-down
trap is sent to the Simple Network Management Protocol (SNMP) manager. An SNMP
trap is not sent if you configure the port for restrictive violation mode. A trap is sent only
if you configure the port to shut down during a security violation.
Reference:
http://www.cisco.com/en/US/products/hw/switches/ps700/products_configuration_guide_chapter09186a008007
f

Front 89

What is the IEEE standard associated with Gigabit Ethernet? (Select two answer
choices)
A. 802.11
B. 802.5
C. 802.3ab
D. 802.3ae
E. 802.3z
F. 802.3u

Back 89

Answer: C, E

Hint 89

Explanation:
The IEEE 802.3z standard describes 1000BASE-SX.
The 1000BaseT standard was released in June 1999, defined by IEEE 802.3ab.
Incorrect Answers:
A. This describes the standard used for wireless networks.
B. This is the standard for token ring networks.
D. On June 17, 2002 the IEEE 802.3ae specification for 10 Gigabit Ethernet was
approved as an IEEE standard by the IEEE Standards Association (IEEE-SA) Standards
Board.
F. IEEE 802.3u describes the standard for 100BASE-TX.

Front 90

Which of the following can lead to the contribution of LAN traffic congestion?
(Select all that apply)
A. Too many hosts in a broadcast domain
B. Full duplex operation
C. Broadcast storms
D. Multicasting
E. Segmentation
F. Low bandwidth

Back 90

Answer: A, C, F

Hint 90

Explanation:
Choice A is correct because the more hosts on a broadcast domain, the more traffic that is
created. Choice Ccontributes to congestion because broadcast storms can become very
problematic, and lead to complete network saturation. Multicasts are similar to
broadcasts in their use on a LAN. Finally, if there is not enough bandwidth, traffic
sessions can time out. This leads to new transmissions and the re-sending of data, which
can lead to more congestion.
Incorrect Answers:
B, E. These are incorrect because full duplex operation and segmented networks actually
result in less congestion.
D. Multicasting can actually alleviate congestion issues, as single streams of information
can reach multiple hosts at the same time, instead of using a series of point to point
connections

Front 91

On a half-duplex Ethernet LAN, two hosts attempt to send data simultaneously,
resulting in a collision. Following this collision, what will the hosts do? (Select all
valid answers)
A. The destination host sends a request to the source for retransmission.
B. The jam signal indicates that the collision has been cleared.
C. The hosts will attempt to resume transmission after a time delay has expired.
D. An electrical pulse indicates that the collision has cleared.
E. The router on the segment will signal that the collision has cleared.
F. The hosts will do nothing, as the higher layers are responsible for data error correction
and re-transmission

Back 91

Answer: C

Hint 91

Explanation:
When a host on an Ethernet LAN has information to send, the following steps are taken:
1. A device with a frame to send listens until Ethernet is not busy.
2. When the Ethernet is not busy, the sender begins sending the frame.
3. The sender listens to make sure that no collision occurred.
4. Once the senders hear the collision, they each send a jamming signal, to ensure that all
stations recognize the collision.
5. After the jamming is complete, each sender randomizes a timer and waits that long.
6. When each timer expires, the process starts over with step 1

Front 92

Which of the following statements correctly describe the differences between
half-duplex and full-duplex Ethernet? (Select two answer choices.)
A. Full-duplex Ethernet uses CSMA/CD to prevent collisions.
B. Half-duplex Ethernet uses a loopback circuit to detect collisions.
C. A full-duplex Ethernet card allows 20Mbps for data transmission.
D. Full-duplex Ethernet makes use of two pairs of wires for data.
E. An Ethernet hub can operate both half and full duplex simultaneously

Back 92

Answer: B, D

Hint 92

Explanation:
Half-duplex Ethernet send and receives on the same line, so a loopback needs to be set to
detect collisions. Alternatively, full-duple Ethernet doesn't have to because it uses two
pairs of wire, one to send and the other to receive. Collisions are not possible on full
duplex Ethernet networks.
Incorrect Answers:
A. Full duplex uses both pairs of wires, so transmissions are sent on the first pair, and
data that is received come in on the other pair. This prevents collisions.
C. Full duplex allows for data to be sent and received at the same time. It will not double
the amount of bandwidth at any given time. The speed of the Ethernet link will remain at
10/100.
E. Hubs are shared devices and can only support one mode, unlike switches.

Front 93

Why is full-duplex Ethernet superior to its single-duplex counterpart? (Select two
answer choices.)
A. It uses inexpensive hubs
B. It operates without collisions
C. It operates on switches
D. It provides faster data transfer
E. It utilizes fewer wiring pairs

Back 93

Answer: B, D

Hint 93

Explanation:
Full duplex Ethernet allows concurrent sending and receiving, which allows the full
bandwidth to be used for both sending and receiving. The result is a collision free
network with increased throughput.
Incorrect Answers:
A, C. These are incorrect because full duplex doesn't require hubs or switches. Full
duplex operation can be used on switch and router ports, as well as PC hosts.
E. This is incorrect because full duplex actually uses more wiring pairs. In full duplex,
both wire pairs are used. Half duplex uses only a single pair

Front 94

When you compare the differences between half-duplex and full-duplex Ethernet,
which of the following characteristics are exclusive to half-duplex? (Select two
answer choices)
A. Half-duplex Ethernet operates in a shared collision domain.
B. Half-duplex Ethernet operates in an exclusive broadcast domain.
C. Half-duplex Ethernet has efficient throughput.
D. Half-duplex Ethernet has lower effective throughput.
E. Half-duplex Ethernet operates in an exclusive collision domain

Back 94

Answer: A, D

Hint 94

Explanation:
A single device could not be sending a frame and receiving a frame at the same time
because it would mean that a collision was occurring. So, devices simply chose not to
send a frame while receiving a frame. That logic is called half-duplex logic.
Ethernet switches allow multiple frames to be sent over different ports at the same time.
Additionally, if only one device is connected to a switch port, there is never a possibility
that a collision could occur. So, LAN switches with only one device cabled to each port
of the switch allow the use of full-duplex operation. Full duplex means that an Ethernet
card can send and receive concurrently.
Incorrect Answers:
B. Full duplex effectively doubles the throughput of half-duplex operation, because data
can be both sent and received at the full 10/100 speed.
C, E. In half duplex operation, the network is shared between all devices in the collision
domain.
Reference: CCNA Self-Study CCNA INTRO exam certification Guide (Cisco Press,
ISBN 1-58720-094-5) Page 62-63

Front 95

Two stations on the Certkiller LAN transmit at the same time, resulting in a
collision. What happens when a collision occurs on the network? (Choose all that
apply)
A. Each device on the Ethernet segment stops transmitting for a short time.
B. A jam signal informs all devices that a collision occurred.
C. When data transmission resumes, the devices that were involved in the collision have
priority to transmit.
D. The devices that are involved in the collision stops transmitting for a short time.
E. The collision invokes a random back-off algorithm.

Back 95

Answer: B, D, E

Hint 95

Explanation:
When a host on an Ethernet LAN has information to send, the following steps are taken:
1. A device with a frame to send listens until Ethernet is not busy.
2. When the Ethernet is not busy, the sender begins sending the frame.
3. The sender listens to make sure that no collision occurred.
4. Once the senders hear the collision, they each send a jamming signal, to ensure that all
stations recognize the collision.
5. After the jamming is complete, each sender randomizes a timer and waits that long.
6. When each timer expires, the process starts over with step 1.
Incorrect Answers:
A. Only the stations involved in the collision stop transmitting for a short time, not all
stations on the LAN.
C. No priority is given to any stations once a collision has occurred.

Front 96

Which of the following are true of Ethernet technology?
A. Hosts use a logical ring topology.
B. Hosts use a logical bus topology
C. Hosts must wait for an electronic signal to transfer data.
D. Hosts are directly connected to a wiring concentrator called a MSAU.
E. None of the above

Back 96

Answer: B

Hint 96

Explanation:
LAN topologies define the manner in which network devices are organized. Four
common LAN topologies exist: bus, ring, star, and tree. These topologies are logical
architectures, but the actual devices need not be physically organized in these
configurations. Logical bus and ring topologies, for example, are commonly organized
physically as a star. A bus topology is a linear LAN architecture in which transmissions
from network stations propagate the length of the medium and are received by all other
stations. Of the three most widely used LAN implementations, Ethernet/IEEE 802.3
networks, including 100BaseT, implement a bus topology, which is illustrated in Figure
2-3.
Figure2-3: Some networks implement a local bus topology

Front 97

With regard to Ethernet media access methods, which of the following are true?
(Choose all that apply.)
A. A device waits for an electronic signal before transmitting.
B. A device listens and waits until the media is not busy before transmitting.
C. All devices on an Ethernet segment see data that passes on the network medium.
D. Only the sender and the receiver devices see data that passes on the network medium.
E. Ethernet networks allow you to configured devises with higher transmission priority

Back 97

Answer: B, C

Hint 97

Explanation:
Ethernet uses the CSMA/CD access method.
CSMA/CD logic helps prevent collisions and also defines how to act when a collision
does occur. The CSMA/CD algorithm words like this:
1. A device with a frame to send listens until the Ethernet is not busy.
2. When the Ethernet is not busy, the sender begins sending the frame.
3. The sender listens to make sure that no collision occurred.
4. Once the senders hear the collision, they each send a jamming signal, to ensure that all
stations recognize the collision.
5. After the jamming is complete, each sender randomizes a timer and waits that long.
6 When each timer expires, the process starts over with Step 1.
So, all devices on the Ethernet need to use CSMA/CD to avoid collisions and to recover
when inadvertent collisions occur.
Reference: Cisco CCNA intro 640-821 p.55

Front 98

Which two statements describe the operation of the CSMA/CD access method,
which is in use on the Certkiller network? (Choose two)
A. After a collision, the station that detected the collision has first priority to resend the
lost data.
B. In a CSMA/CD collision domain, stations must wait until the media is not in use
before transmitting.
C. In a CSMA/CD collision domain, multiple stations can successfully transmit data
simultaneously.
D. The use of hubs to enlarge the size of collision domains is one way to improve the
operation of the CSMA/CD access method.
E. After a collision, all stations run a random backoff algorithm. When the backoff delay
period has expired, all stations have equal priority to transmit data.
F. After a collision, all stations involved run an identical backoff algorithm and then
synchronize with each other prior to transmitting data.

Back 98

Answer: B, E

Hint 98

Explanation:
Ethernet networking uses Carrier Sense Multiple
Access with Collision Detect (CSMA/CD), a protocol
that helps devices share the bandwidth evenly
without having two devices transmit at the same time
on the network medium. CSMA/CD was created to
overcome the problem of those collisions
that occur when packets are transmitted
simultaneously from different nodes. And trust me,
good collision management is crucial, because when
a node transmits in a CSMA/CD network, all the
other nodes on the network receive and examine that
transmission. Only bridges and routers can
effectively prevent a transmission from propagating
throughout the entire network! So, how does the
CSMA/CD protocol work? Like this: when a host
wants to transmit over the network, it first checks for
the presence of a digital signal on the wire. If all is
clear (no other host is transmitting), the host will then
proceed with its transmission. But it doesn't stop
there. The transmitting host constantly monitors the
wire to make sure no other hosts begin transmitting.
If the host detects another signal on the wire, it sends
out an extended jam signal that causes all nodes on
the segment to stop sending data (think, busy signal).
The nodes respond to that jam signal by waiting a
while before attempting to transmit again. Backoff
algorithms determine when the colliding stations can
retransmit. If collisions keep occurring after 15 tries,
the nodes attempting to transmit will then time out

Front 99

Which three statements are true about the operation of a full-duplex Ethernet
network, which is being used in the Certkiller LAN? (Choose three)
A. Ethernet hub ports are preconfigured for full-duplex mode.
B. The host network card and the switch port must be capable of operating in full-duplex
mode.
C. There are no collisions in full-duplex mode.
D. In a full-duplex environment, the host network card must check for the availability of
the network media before transmitting.
E. A dedicated switch port is required for each full-duplex node

Back 99

Answer: B, C, E

Hint 99

Explanation:
Half-duplex Ethernet is defined in the original 802.3 Ethernet and Cisco says you only
use one wire pair with a digital signal running in both directions on the wire. It also uses
the CSMA/CD protocol to help prevent collisions and to permit retransmitting if a
collision does occur. If a hub is attached to a switch, it must operate in half-duplex mode
because the end stations must be able to detect collisions. Half-duplex Ethernet-typically
10BaseT-is only about 30 to 40 percent efficient as Cisco sees it, because a large
10BaseT network will usually only give you 3- to 4Mbps-at most.
Full-duplex Ethernet uses two pairs of wires, instead of one wire pair like half duplex.
Also, full duplex uses a point-to-point connection between the transmitter of the
transmitting device and the receiver of the receiving device, which means that with
full-duplex data transfer, you get a faster data transfer compared to half duplex. And
because the transmitted data is sent on a different set of wires than the received data, no
collisions occur. The reason you don't need to worry about collisions is because now
Full-duplex Ethernet is like a freeway with multiple lanes instead of the single-lane road
provided by half duplex. Full-duplex Ethernet is supposed to offer 100 percent efficiency
in both directions; this means you can get 20Mbps with a 10Mbps Ethernet running full
duplex, or 200Mbps for FastEthernet

Front 100

The Certkiller network administrator wants to use a router named CK1 to segment
the local network. What are some of the advantages of using CK1 to segment the
network? (Choose two)
A. Routers generally cost less than switches
B. Filtering can occur based on Layer 3 information
C. Broadcasts are not forwarded across the router
D. Broadcasts are eliminated
E. Adding a router to the network decreases latency
F. Routers can generally support more LAN ports than switches

Back 100

Answer: B, C

Front 101

Which of the following devices can the Certkiller network administrator use to
segment the LAN? (Choose all that apply)
A. Hubs
B. Repeaters
C. Switches
D. Bridges
E. Routers
F. Media Converters
G. All of the above

Back 101

Answer: C, D, E

Hint 101

Explanation:
Switches and bridges forward broadcast but routers do not forward broadcasts by default
(they can via the "ip helper-address" command).
Switches, bridges and routers can segment an Ethernet collision domain via the use of
VLAN's
Incorrect Answers:
A. Hubs is incorrect because a hub doesn't segment a network, it only allows more hosts
on one. Hubs operate at layer one, and is used primarily to physically add more stations
to the LAN.
B. This also incorrect because the job of a repeater is to repeat a signal so it can exceed
distance limitations. It also operates at layer one and provides no means for logical LAN
segmentation.
F. This is incorrect because media converters work by converting data from a different
media type to work with the media of a LAN. It also operates at layer one and provides
no means for logical LAN segmentation

Front 102

The Certkiller corporate LAN consists of one large flat network. You decide to
segment this LAN into two separate networks with a router. What will be the affect
of this change?
A. The number of broadcast domains will be decreased.
B. It will make the broadcasting of traffic between domains more efficient between
segments.
C. It will increase the number of collisions.
D. It will prevent segment 1's broadcasts from getting to segment 2.
E. It will connect segment 1's broadcasts to segment 2.

Back 102

Answer: D

Hint 102

Explanation
A router does not forward broadcast traffic. It therefore breaks up a broadcast domain,
reducing unnecessary network traffic. Broadcasts from one segment will not be seen on
the other segment.
Incorrect Answers:
A. This will actually increase the number of broadcast domains from one to two.
B. All link level traffic from segment one to segment two will now need to be routed
between the two interfaces of the router. Although this will reduce the traffic on the LAN
links, it does also provide a less efficient transport between the segments.
C. Since the network size is effectively cut into half, the number of collisions should
decrease dramatically.
E. Broadcasts from one segment will be completely hidden from the other segment

Front 103

You want to influence the root bridge selection within the Certkiller LAN. Which
two values are used by spanning tree protocol to elect a root bridge? (Choose two.)
A. Amount of RAM
B. Speed of the links
C. IOS Version
D. MAC Address
E. Bridge Priority
F. IP Address
G. Router ID

Back 103

Answer: D, E

Front 104

A Certkiller Ethernet switch receives a unicast frame with a destination MAC that is
listed in the switch table. What will this switch do with the frame?
A. The switch will forward the frame to a specific port
B. The switch will forward the frame to all ports except the port on which it was received
C. The switch will return a copy of the frame out the source port
D. The switch will not forward unicast frames
E. The switch will remove the destination MAC from the switch table
F. None of the above

Back 104

Answer: A

Front 105

In which circumstance are multiple copies of the same unicast frame likely to be
transmitted in the Certkiller Switched LAN?
A. During high traffic periods
B. In an improperly implemented redundant topology
C. After broken links are re-established
D. When upper-layer protocols require high reliability
E. When a dual ring topology is in use
F. None of the above

Back 105

Answer: B

Front 106

The Certkiller network administrator needs to a switch named CK1 to become the
root bridge for a redundant path switched network. What can be done to ensure
that CK1 will always assume the role as the root bridge?
A. Assign the switch a higher MAC address than the other switches in the network have
B. Establish a direct link from the switch to all other switches in the network
C. Configure the switch full-duplex operation and configure the other switches for
half-duplex operation
D. Configure the switch so that it has lower priority than other switches in the network
E. None of the above

Back 106

Answer: D

Front 107

CK1 is a switch in the Certkiller network. Why will CK1 never learn the broadcast
address?
A. Broadcast frames are never sent to switches
B. A broadcast frame is never forwarded by a switch
C. Broadcasts only use network layer addressing
D. A broadcast address will never be the source address of a frame
E. Broadcast addresses use an incorrect format for the switching table
F. None of the above

Back 107

Answer: D

Hint 107

Explanation:
There three different address types:
* Unicast : One source to One destination
* Broadcast: One source to multiple destination
* Multicast: One source to multiple destination joined to group
On unicast or broadcast or multicast communication, the source address is always the
unicast address but the destination address can be unicast, broadcast or multicast

Front 108

The system LED is amber on a new Certkiller Catalyst 2950 series switch. What does
this indicate?
A. The system is powered up and operational.
B. The system is sensing excessive collisions.
C. The system is forwarding traffic.
D. The system is not powered up.
E. The system is malfunctioning.
F. None of the above

Back 108

Answer: E

Hint 108

Explanation:
While the switch powers on, it begins POST, a series of tests. POST runs automatically
to verify that the switch functions properly. When the switch begins POST, the system
LED is off. If POST completes successfully, the LED turns green. If POST fails, the LED
turns amber.
Note: POST failures are usually fatal. Call Cisco Systems if your switch does not pass
POST

Front 109

Some of the older Certkiller switches store the entire frame before forwarding it to
the destination. What are two effects on network performance of configuring a
switch to do this? (Choose two)
A. Filtering of collision fragments only
B. Decreased latency
C. Increased latency
D. Filtering of all frame errors
E. Increase in switch operating speed
F. Propagation of corrupted or damaged frames

Back 109

Answer: C, D

Hint 109

Explanation:
Switches that store the entire frame before forwarding to the destination are using the
store and forward process. This mode copies the entire frame into memory, computes the
Cyclic Redundancy Check (CRC) for errors, and then looks up the destination MAC
address and forwards the frame. This is slow but offers the best solution for error
correction without affecting the entire backbone in retransmission. This gives us the best
method for filtering errors from traversing the network, but at a cost of higher latency.

Front 110

As a Certkiller trainee you are required to set the default gateway on a Cisco switch
to the IP address of 192.168.1.115. Which IOS command should you use?
A. CertK Switch(config)# ip route-default 192.168.1.115
B. CertK Switch(config)# ip default-gateway 192.168.1.115
C. CertK Switch(config)# ip route 192.168.1.115 0.0.0.0
D. CertK Switch(config)# ip default-network 192.168.1.115
E. None of the above

Back 110

Answer: B

Hint 110

Explanation:
Use the "ip default-gateway" command to enter the IP address of the next-hop router
interface that is directly connected to the switch where a default gateway is being
configured. The default gateway receives IP packets with unresolved destination IP
addresses from the switch.
Once the default gateway is configured, the switch has connectivity to the remote
networks with which a host needs to communicate.

Front 111

You need to perform some initial configuration tasks on a new Certkiller switch.
What is the purpose of assigning an IP address to a switch?
A. To provide local hosts with a default gateway address
B. To allow remote management of the switch.
C. To allow the switch to respond to ARP requests between two hosts
D. To ensure that hosts on the same LAN can communicate with each other.
E. None of the above

Back 111

Answer: B

Hint 111

Explanation:
Switch is a layer 2 device and doesn't use network layer for packet forwarding. The IP
address may be used only for administrative purposes such as Telnet access or for
network management purposes.

Front 112

You need to perform some initial configuration tasks on a new Certkiller switch
What are the possible trunking modes for this switch port? (Choose three)
A. Transparent
B. Auto
C. On
D. Desirable
E. Client
F. Forwarding
G. Learning

Back 112

Answer: B, C, D

Hint 112

Explanation:
Here, the trunk link is identified by its physical location as the switch module number
and port number. The trunking mode can be set to any of the following:
on- This setting places the port in permanent trunking mode. The corresponding switch
port at the other end of the trunk should be similarly configured because negotiation is
not
allowed. The encapsulation or identification mode should also be manually configured.
off-This setting places the port in permanent non-trunking mod. the port will attempt
to convert the link to non-trunking mode.
desirable-Selection this port will actively attempt to convert the link into trunking
mode. If the far end switch port is configured to on, desirable, or auto mode, trunking
will be successfully negotiated.
auto-The port will be willing to convert the link into trunking mode. If the far end
switch
port is configured to on or desirable, trunking will be negotiated. By default, all Fast
Ethernet and Gigabit Ethernet links that are capable of negotiating using DTP are
configured to this mode. Because of the passive negotiation behavior, the link will never
become a trunk, if both ends of the link are left to the auto default.
nonegotiate-The port is placed in permanent trunking mode, but no DTP frames are
generated for negotiation. The far end switch port must be manually configured for
trunking mode

Front 113

An administrator would like to configure a switch over a virtual terminal
connection from locations outside of the local LAN. Which of the following are
required in order for the switch to be configured from a remote location? (Choose
two)
A. The switch must be reachable through a port connected to its management VLAN.
B. The switch console port must be connected to the Ethernet LAN.
C. The switch must be fully configured as an SNMP agent.
D. The switch must be configured with an IP address, subnet mask, and default gateway.
E. The switch management VLAN must be created and have a membership of at least one
switch port.
F. The switch must be connected to a router over a VLAN trunk

Back 113

Answer: A, D

Hint 113

Explanation:
In order the telnet to any Cisco device, the device must be reachable from the remote
location. For a Cisco switch to be reachable from remote locations, it must have an IP
address, subnet mask, and default gateway assigned.
Communication with the switch management interfaces is through the switch IP address.
The IP address is associated with the management VLAN, which by default is VLAN 1

Front 114

While troubleshooting a connectivity problem, the Certkiller network administrator
notices that a port status LED on a Cisco Catalyst Series switch is alternating
between green and amber. Which condition could this indicate?
A. The port is experiencing errors
B. The port has ac active link with normal traffic activity
C. The port blocked by spanning tree
D. The port is administratively disabled
E. None of the above

Back 114

Answer: A

Front 115

You are the administrator of the Certkiller LAN and you have been reviewing error
logs of networking devices and notice a large number of errors associated with
several MAC addresses. You suspect that some of the errors are being generated by
the routers. Which router commands will allow you to find the ip address associated
with each MAC address? (Choose two)
A. show arp
B. show version
C. show address
D. show hosts
E. show interface
F. show protocols

Back 115

Answer: A, E

Hint 115

Explanation:
The "show arp" command Displays the entries in the ARP table, including their layer 2
MAC address and layer 3 IP address.
Example:
The following is the output for the show arp command on Router 1:
CK1 # show arp
Protocol Address Age (min) Hardware Addr Type Interface
Internet 10.0.0.3 0 0004.dd0c.ffcb ARPA Ethernet01
Internet 10.0.0.1 - 0004.dd0c.ff86 ARPA Ethernet0
To see the MAC (hardware) address of the router interfaces as well as their IP addresses,
use the "show interfaces" command as shown in the example below:
CK1 # show interfaces
Ethernet 0 is up, line protocol is up
Hardware is MCI Ethernet, address is 0000.0c00.750c (bia 0000.0c00.750c)
Internet address is 10.108.28.8, subnet mask is 255.255.255.0
MTU 1500 bytes, BW 10000 Kbit, DLY 100000 usec, rely 255/255, load 1/255

Front 116

The Certkiller network administrator issues the ping 192.168.2.5 command and
successfully tests connectivity to a host that has been newly connected to the
network. Which protocols were used during the test? (Choose two)
A. ARP
B. CDP
C. DHCP
D. DNS
E. ICMP

Back 116

Answer: A, E

Hint 116

Explanation:
ARP finds the hardware address of a host from a known IP address. Here's how it works:
when IP has a datagram to send, it must inform a Network Access protocol, such as
Ethernet or Token Ring, of the destination's hardware address on the local network. (It
has already been informed by upper-layer protocols of the destination's IP address.) If IP
doesn't find the destination host's hardware address in the ARP cache, it uses ARP to find
this information.
ICMP works at the Network layer and is used by IP for many different services. ICMP is
a management protocol and messaging service provider for IP. Its messages are carried as
IP datagrams. RFC 1256 is an annex to ICMP, which affords hosts' extended capability in
discovering routes to gateways. Periodically, router advertisements are announced over
the network, reporting IP addresses for the router's network interfaces. Hosts listen for
these network infomercials to acquire route information. A router solicitation is a request
for immediate advertisements and may be sent by a host when it starts up

Front 117

The Certkiller network administrator wants to control which user hosts can access
the network based on their MAC address. What will prevent workstations with
unauthorized MAC addresses from connecting to the network through a switch?
A. BPDU
B. Port security
C. RSTP
D. STP
E. VTP
F. Blocking mode
G. None of the above

Back 117

Answer: B

Hint 117

Explanation:
Understanding How Port Security Works:
You can use port security to block input to an Ethernet, Fast Ethernet, or Gigabit Ethernet
port when the MAC address of the station attempting to access the port is different from
any of the MAC addresses specified for that port. Alternatively, you can use port security
to filter traffic destined to or received from a specific host based on the host MAC
address.
When a secure port receives a packet, the source MAC address of the packet is compared
to the list of secure source addresses that were manually configured or autoconfigured
(learned) on the port. If a MAC address of a device attached to the port differs from the
list of secure addresses, the port either shuts down permanently (default mode), shuts
down for the time you have specified, or drops incoming packets from the insecure host.
The port's behavior depends on how you configure it to respond to a security violation.
If a security violation occurs, the Link LED for that port turns orange, and a link-down
trap is sent to the Simple Network Management Protocol (SNMP) manager. An SNMP
trap is not sent if you configure the port for restrictive violation mode. A trap is sent only
if you configure the port to shut down during a security violation.
Reference:
http://www.cisco.com/en/US/products/hw/switches/ps700/products_configuration_guide_chapter09186a008007
f

Front 118

While troubleshooting an issue in the Certkiller LAN you notice that a network
interface port has collision detection and carrier sensing enabled on a shared
twisted pair network. From this statement, what is known about the network
interface port?
A. This is an Ethernet port operating at half duplex
B. This is an Ethernet port operating at full duplex
C. This is a port on a network interface card in a PC
D. This is 10 MB/s switch port
E. This is a 100 MB/s switch port
F. None of the above

Back 118

Answer: A

Front 119

When a switch port is used as a VLAN trunk, which of the following trunk modes
are valid? (Select all that apply.)
A. Blocking
B. Auto
C. Desirable
D. On
E. Transparent
F. Learning

Back 119

Answer: B, C, D

Front 120

Which of following VLAN frame encapsulation types are configurable on a Cisco
switch? (Select two answer choices.)
A. VTP
B. 802.1Q
C. LLC
D. ISL
E. CDP
F. PAP

Back 120

Answer: B, D

Hint 120

Explanation:
ISL and 802.1Q are the two trunking encapsulations that can be configured on a Cisco
switch. ISL is Cisco proprietary and 802.1Q is the IEEE standard method.
Incorrect Answers:
A. VTP is the VLAN Trunking Protocol, which is used to carry VLAN information
across the trunks. The question is asking for the encapsulation options for the trunk,
which will be used by VTP.
C. LLC is the Logical Link Control, which is a sub-layer of the data link layer.
E. CDP is the Cisco Discovery Protocol, which is used by Cisco devices to discover
information on neighboring Cisco devices.
F. PAP is the Password Authentication Protocol, which is used as an authentication
mechanism on PPP links

Front 121

Certkiller users have noticed extremely slow network performance, intermittent
connectivity, and connection losses. After entering the "show interfaces" command,
you notice that the Ethernet interface is configured as 100 Mbps full-duplex and
that there is evidence of late collisions. What could be the cause of this problem?
A. Duplex mismatch
B. A routing loop
C. Trunking mode mismatch
D. Improperly configured root bridge
E. Improperly configured static VLAN
F. None of the above

Back 121

Answer: A

Hint 121

Explanation:
A duplex mismatch may result in performance issues, intermittent connectivity, and loss
of communication. When troubleshooting NIC issues, verify that the NIC and switch are
using a valid configuration. Some third-party NIC cards may fall back to half-duplex
operation mode, even though both the switchport and NIC configuration have been
manually configured for 100 Mbps, full-duplex. This behavior is due to the fact that NIC
autonegotiation link detection is still operating when the NIC has been manually
configured. This causes duplex inconsistency between the switchport and the NIC.
Symptoms include poor port performance and frame check sequence (FCS) errors that
increment on the switchport. To troubleshoot this issue, try manually configuring the
switchport to 100 Mbps, half-duplex. If this action resolves the connectivity
problems,you may be running into this NIC issue. Try updating to the latest drivers for
your NIC, or contact your NIC card vendor for additional support.
Reference:
http://www.cisco.com/en/US/products/hw/switches/ps700/products_tech_note09186a00800a7af0.shtml

Front 122

You are experiencing intermittent issues relating to congestion within the Certkiller
network. What are the possible causes of congestion on this LAN? (Choose all that
apply)
A. A broadcast domain with too many hosts.
B. Full duplex operation.
C. Broadcast storms.
D. Multicasting.
E. Network Segmentation.
F. Low bandwidth

Back 122

Answer: A, C, F

Hint 122

Explanation:
A LAN segment with too many hosts can mean that there are a large number of stations
contending for bandwidth. It can also mean an increase in the number of collisions on the
segment, which can cause further congestion issues. Broadcast storms are the result of a
large number of broadcasts sent over the LAN. Because each station listens to these
broadcast messages, congestion can occur quickly. Finally, low bandwidth can simply
mean that the LAN can not process all of the LAN traffic that is being sent. This can
mean that TCP sessions are retransmitted, which can lead to additional congestion.
Incorrect Answers:
B. This can alleviate congestion, as data can be sent and received at the same time. In
addition, collisions are not possible in a full duplex LAN.
D. Multicasting can actually alleviate congestion issues, as single streams of information
can reach multiple hosts at the same time, instead of using a series of point to point
connections.
E. Segmentation breaks up a large LAN into multiple, smaller LANS. This will mean
fewer hosts per broadcast domain.

Front 123

If an ethernet port on router CK1 was assigned an IP address of 172.16.112.1/20,
what is the maximum number of hosts allowed on this LAN subnet?
A. 2046
B. 1024
C. 4096
D. 8190
E. 4094
F. None of the above

Back 123

Answer: E

Hint 123

Explanation:
Since a /20 equates to 12 bits used for the subnet mask, 4094 hosts can be uniquely
addressed.
Number of Bits in the Host or
Maximum number of Hosts or
Subnet Field
Subnets (
2n-2)
1 0
2 2
3 6
4 14
5 30
6 62
7 126
8 254
9 510
10 1022
11 2046
12 4094
13 8190
14 16,382

Front 124

From where does a small network typically get its IP network addresses or IP
block?
A. From the Internet Domain Name Registry (IDNR)
B. From the Internet Assigned Numbers Authority (IANA)
C. From the Internet Service Provider (ISP)
D. From the Internet Architecture Board (IAB)
E. None of the above

Back 124

Answer: C

Hint 124

Explanation:
Normally a small network will be assigned a number of IP addresses from their ISP, or in
some cases, such as DSL and cable modem, a single dynamic IP address will be assigned
by the ISP. Only very large networks requiring a large IP block (normally more than a
/20) will register with IANA, RIPE, or ARIN (American Registry of Internet Numbers)
to obtain their IP addresses

Front 125

If a host on a network has the address 172.16.45.14/30, what is the address of the
subnetwork to which this host belongs?
A. 172.16.45.0
B. 172.16.45.4
C. 172.16.45.8
D. 172.16.45.12
E. 172.16.45.18

Back 125

Answer: D

Hint 125

Explanation:
The last octet in binary form is 00001110. Only 6 bits of this octet belong to the subnet
mask. Hence, the subnetwork is 172.16.45.12.

Front 126

Which two of the addresses below are available for host addresses on the Certkiller
subnet 192.168.15.19/28? (Select two answer choices)
A. 192.168.15.17
B. 192.168.15.14
C. 192.168.15.29
D. 192.168.15.16
E. 192.168.15.31
F. None of the above

Back 126

Answer: A, C

Hint 126

Explanation:
The network uses a 28bit subnet (255.255.255.240). This means that 4 bits are used for
the networks and 4 bits for the hosts. This allows for 14 networks and 14 hosts (2n-2).
The last bit used to make 240 is the 4th bit (16) therefore the first network will be
192.168.15.16. The network will have 16 addresses (but remember that the first address
is the network address and the last address is the broadcast address). In other words, the
networks will be in increments of 16 beginning at 192.168.15.16/28. The IP address we
are given is 192.168.15.19. Therefore the other host addresses must also be on this
network. Valid IP addresses for hosts on this network are: 192.168.15.17-192.168.15.30.
Incorrect Answers:
B. This is not a valid address for this particular 28 bit subnet mask. The first network
address should be 192.168.15.16.
D. This is the network address.
E. This is the broadcast address for this particular subnet

Front 127

Certkiller has a Class C network and you need ten subnets. You wish to have as
many addresses available for hosts as possible. Which one of the following subnet
masks should you use?
A. 255.255.255.192
B. 255.255.255.224
C. 255.255.255.240
D. 255.255.255.248
E. None of the above

Back 127

Answer: C

Hint 127

Explanation:
Using the 2n-2 formula, we will need to use 4 bits for subnetting, as this will provide for
24-2 = 14 subnets. The subnet mask for 4 bits is then 255.255.255.240.
Incorrect Answers:
A. This will give us only 2 bits for the network mask, which will provide only 2
networks.
B. This will give us 3 bits for the network mask, which will provide for only 6 networks.
D. This will use 5 bits for the network mask, providing 30 networks. However, it will
provide for only for 6 host addresses in each network, so C is a better choice.

Front 128

You have a single Class C IP address and a point-to-point serial link that you want
to implement VLSM on. Which subnet mask is the most efficient for this point to
point link?
A. 255.255.255.0
B. 255.255.255.240
C. 255.255.255.248
D. 255.255.255.252
E. 255.255.255.254
F. None of the above

Back 128

Answer: D

Hint 128

Explanation:
For a single point to point link, only 2 IP addresses are required, one for the serial
interface of the router at each end. Therefore, the 255.255.255.252 subnet mask is often
used for these types of links, as no IP addresses are wasted.

Front 129

You have a network that supports VLSM and you need to reduce IP address waste
in your point to point WAN links. Which of the masks below would you use?
A. /38
B. /30
C. /27
D. /23
E. /18
F. /32

Back 129

Answer: B

Hint 129

Explanation:
For a single point to point link, only 2 IP addresses are required, one for the serial
interface of the router at each end. Therefore, the 255.255.255.252 subnet mask is often
used for these types of links because no IP addresses are wasted. The subnet mask
255.255.255.252 is a /30, so answer B is correct.
Incorrect Answers:
A. The largest mask that can be used is the single IP host mask, which is /32. It is not
possible to use a /38 mask, unless of course IPv6 is being used.
C, D, E. These masks will provide for a larger number of host addresses, and since only 2
IP addresses are needed for a point to point link, these extra addresses are wasted.
F: No available host addresses with a /32 mask

Front 130

What is the maximum number of IP addresses that can be assigned to hosts on a
Certkiller subnet that uses the 255.255.255.224 subnet mask?

Back 130

Answer: D

Hint 130

Explanation:
The subnet mask 255.255.255.224 means that there are 27 network bits. The remaining 5
bits are the host bits. The maximum possible combinations with 5 bits are 25 = 32. As all
zero's and all one's hosts are not allowed so, maximum number of valid hosts with the
mask 255.255.255.224 are 25 -2 =32-2 = 30 Hosts

Front 131

In a Certkiller network that supports VLSM, which network mask should be used
for point-to-point WAN links in order to reduce waste of IP addresses?
A. /24
B. /30
C. /27
D. /26
E. /32
F. None of the above

Back 131

Answer: B

Hint 131

Explanation:
A 30-bit mask is used to create subnets with two valid host addresses. This is the exact
number needed for a point-to-point connection

Front 132

The network 172.25.0.0 has been divided into eight equal subnets. Which of the
following IP addresses can be assigned to hosts in the third subnet if the ip
subnet-zero command is configured on the router? (Choose three)
A. 172.25.78.243
B. 172.25.98.16
C. 172.25.72.0
D. 172.25.94.255
E. 172.25.96.17
F. 172.25.100.16

Back 132

Answer: A, C, D

Hint 132

Explanation:
If we divide the address 172.25.0.0 in 8 subnets, the resulting subnets will be
1. 172.25.0.0
2. 172.25.32.0
3. 172.25.64.0 This is the third subnet
4. 172.25.96.0
5. 172.25.128.0
6. 172.25.160.0
7. 172.25.192.0
8. 172.25.224.0
Addresses that fall in the 3rd subnet will be from 172.25.64.0 ---- 172.25.95.255
Choices A, C and D lie in this network range.

Front 133

What is the subnet address of the host with an IP address of 172.16.159.159/22?
A. 172.16.128.0
B. 172.16.156.0
C. 172.16.159.128
D. 172.16.159.0
E. 172.16.192.0
F. 172.16.0.0
G. None of the above

Back 133

Answer: B

Hint 133

Explanation:
In this question there are a total of 6 bits borrowed from the host portion with the subnet
mask 255.255.252.0. This will leave us 64 networks with 1022 and the IP subnets for
each will be a multiple of 4. Some of the networks are as follows:
/22 172.16.148.0 - 255.255.252.0 - 1022 hosts
/22 172.16.152.0 - 255.255.252.0 - 1022 hosts
/22 172.16.156.0 - 255.255.252.0 - 1022 hosts
/22 172.16.160.0 - 255.255.252.0 - 1022 hosts
/22 172.16.164.0 - 255.255.252.0 - 1022 hosts
/22 172.16.168.0 - 255.255.252.0 - 1022 hosts
/22 172.16.172.0 - 255.255.252.0 - 1022 hosts
/22 172.16.176.0 - 255.255.252.0 - 1022 hosts

Front 134

You are a systems administrator and you are about to assign static IP addresses to
various servers on your network. For the network 192.168.20.24/29 the router is
assigned to the first usable host address, while the last usable host address goes to
your Sales server. Which one of the following commands would you enter into the
IP properties box of the sales server?
A. IP address: 192.168.20.14
Subnet Mask: 255.255.255.248
Default Gateway: 192.168.20.9
B. IP address: 192.168.20.254
Subnet Mask: 255.255.255.0
Default Gateway: 192.168.20.1
C. IP address: 192.168.20.30
Subnet Mask 255.255.255.248
Default Gateway: 192.168.20.25
D. IP address: 192.168.20.30
Subnet Mask 255.255.255.240
Default Gateway: 192.168.20.17
E. IP address: 192.168.20.30
Subnet Mask 255.255.255.240
Default Gateway: 192.168.20.25

Back 134

Answer: C

Hint 134

Explanation
A subnet mask uses 29 bits. This means that it uses 5 bits in the 4th octet. This equates to
255.255.255.248. This network has 3 bits for hosts. Using the 2n-2 formula (23-2) in this
case), we are left with 6 (2*2*2 - 2 = 6) host addresses. 192.168.20.24 is the network
address. Therefore the next address (192.168.20.25) would be the first host address. This
address must be assigned to the router, which serves as the gateway for the network. The
last available host address would be 192.168.20.30 (192.168.20.24+6). This address is
assigned to the server. The broadcast address is 192.168.20.31

Front 135

You've been assigned a single Class C address. From this, you need 8 subnets, and
your subnet mask is 255.255.255.224. Which one of the following configuration
commands would you have to use before you begin?
A. Router(config)# ip classless
B. Router(config)# ip subnet-zero
C. Router(config)# ip version 6
D. Router(config)# no ip classful
E. Router(config)# ip unnumbered
F. Router(config)# ip all-nets

Back 135

Answer: B

Hint 135

Explanation: To get 8 subnets from a class C address, and a mask of 255.255.255.224
use the reserved subnet space. To do this, you need the command 'ip subnet-zero.'
This will allow the router to use the very first subnet, which is normally reserved
and unused as the network address.Prior to Cisco IOS(r) Software Release 12.0,
Cisco routers, by default, did not allow an IP address belonging to subnet zero to be
configured on an interface. However, if a network engineer working with a Cisco
IOS software release older than 12.0 finds it safe to use subnet zero, the ip
subnet-zero command in the global configuration mode can be used to overcome
this restriction. As of Cisco IOS Software Release 12.0, Cisco routers now have ip
subnet-zero enabled by default, but if the network engineer feels that it is unsafe to
use subnet zero, the no ip subnet-zero command can be used to restrict the use of
subnet zero addresses.
In versions prior to Cisco IOS Software Release 8.3, the service subnet-zero command
was used.
It should be noted that even though it was discouraged, the entire address space including
subnet zero and the all-ones subnet have always been usable. The use of the all-ones
subnet was explicitly allowed and the use of subnet zero is explicitly allowed since Cisco
IOS Software Release 12.0. Even prior to Cisco IOS Software Release 12.0, subnet zero
could be used by entering the ip subnet-zero global configuration command.
On the issue of using subnet zero and the all-ones subnet, RFC 1878 states, "This practice
(of excluding all-zeros and all-ones subnets) is obsolete. Modern software will be able to
utilize all definable networks." Today, the use of subnet zero and the all-ones subnet is
generally accepted and most vendors support their use. However, on certain networks,
particularly the ones using legacy software, the use of subnet zero and the all-ones subnet
can lead to problems

Front 136

Which command on router Certkiller A will assign the last usable IP address from
the 192.168.32.128/28 subnetwork to a router interface?
A. Certkiller A(config-if)# ip address 192.168.32.142 255.255.255.240
B. Certkiller A(config-if)# ip address 192.168.32.143 255.255.255.240
C. Certkiller A(config-if)# ip address 192.168.32.158 255.255.255.240
D. Certkiller A(config-if)# ip address 192.168.32.145 255.255.255.240
E. Certkiller A(config-if)# ip address 192.168.32.144 255.255.255.240
F. Certkiller A(config-if)# ip address 192.168.32.158 255.255.255.240
G. None of the above

Back 136

Answer: A

Hint 136

Explanation:
The last usable IP address would be 128 + (16-2) = 142 because only the last 4 bits of the
last octet are used for host addressing.

Front 137

A host on the Certkiller network has been configured with the IP address
10.16.3.66/23. Which two statements describe this IP address? (Choose two)
A. The broadcast address of the subnet is 10.16.3.255 255.255.254.0.
B. This network is not subnetted.
C. The last valid host address in the subnet is 10.16.2.254 255.255.254.0
D. The subnet address is 10.16.3.0 255.255.254.0.
E. The lowest host address in the subnet is 10.16.2.1 255.255.254.0

Back 137

Answer: A, E

Hint 137

Explanation:
A subnet mask of /23 translates to 255.255.254.0 and will provide for up to 512 IP
addresses.
If we take the 10.16.X.X network using the /23 subnet mask, the first network available is
10.16.0.0/23, which will provide host address from 10.16.0.1 to 10.16.2.254, with
10.16.2.255 being the broadcast address. The next available network in the 10.16.X.X
covers our example in this question of 10.16.3.66.
In this case, the first useable IP address is (10.16.2.1 choice E), and the broadcast address
is 10.16.3.255 (choice A).
In closing, the partial reference table on IPv4 subnets:
CIDR | Net mask | Addresses
-----+-----------------+-----------
/18 | 255.255.192.0 | 16384
/19 | 255.255.224.0 | 8192
/20 | 255.255.240.0 | 4096
/21 | 255.255.248.0 | 2048
/22 | 255.255.252.0 | 1024
/23 | 255.255.254.0 | 512
/24 | 255.255.255.0 | 256
/25 | 255.255.255.128 | 128
/26 | 255.255.255.192 | 64
/27 | 255.255.255.224 | 32
/28 | 255.255.255.240 | 16

Front 138

The Certkiller network administrator has subnetted the 172.16.0.0 network using a
subnet mask of 255.255.255.192. A duplicate IP address of 172.16.2.121 has
accidentally been configured on workstation CK1 in this network. The technician
must assign this workstation a new IP address within that same subnetwork. Which
address should be assigned to CK1 ?
A. 172.16.1.64
B. 172.16.1.80
C. 172.16.2.80
D. 172.16.2.64
E. 172.16.2.127
F. 172.16.2.128
G. None of the above

Back 138

Answer: C

Hint 138

Explanation:
A subnet mask of 255.255.255.192 (/26) will provide us with 4 subnet (2 usable) each
with 62 usable hosts per network. So in our example the four networks will be:
172.16.2.1-62
172.16.2.65-126
172.16.2.129-190
172.16.2.193-254
Since we know that the host must be in the same IP subnet as 172.16.2.120, only choice
C is correct

Front 139

You need to configure NAT on a Certkiller router that is connected to the Internet.
To do so, you must determine what the Inside Global IP addresses will be. What
does the "Inside Global" address represent in the configuration of NAT?
A. The summarized address for all of the internal submitted addresses
B. A registered address that represents that represents an inside host to an outside
network
C. A globally unique, private IP address assigned to a host on the inside network
D. The MAC address of the router used by inside hosts to connect to the Internet
E. None of the above

Back 139

Answer: B

Front 140

Which one of the following varieties of NAT utilizes different ports to map multiple
IP addresses to a single globally registered IP address?
A. Static NAT
B. Port loading
C. NAT Overloading
D. Dynamic NAT
E. Overlapping
F. None of the above

Back 140

Answer: C

Hint 140

Explanation:
Port address translation, or NAT overloading, uses transport layer port information to
dynamically create NAT entries. This is also known as one to many network address
translation.
Incorrect Answers:
A. Static NAT is known as one to one NAT, and is used to map a single IP address to a
single registered IP address. It is often used for servers that need to be accessed via the
Internet.
B, D: This is the incorrect term, and is not used

Front 141

In any NAT (network address translation) configuration, what is the Inside Global
IP address?
A. The summarized address for all internal subnetted addresses.
B. A private IP address assigned to a host on the inside network.
C. A registered address that represents an inside host to an outside network.
D. A unique IP address used on an internal network
E. Non of the above

Back 141

Answer: C

Hint 141

Explanation:
With NAT, Cisco defines 4 different types of addresses as follows:
* Inside local address - The IP address assigned to a host on the inside network. This is
the address configured as a parameter of the computer's OS or received via dynamic
address allocation protocols such as DHCP. The address is likely not a legitimate IP
address assigned by the Network Information Center (NIC) or service provider.
* Inside global address - A legitimate IP address assigned by the NIC or service
provider that represents one or more inside local IP addresses to the outside world.
* Outside local address - The IP address of an outside host as it appears to the inside
network. Not necessarily a legitimate address, it is allocated from an address space
routable on the inside.
* Outside global address - The IP address assigned to a host on the outside network by
the host's owner. The address is allocated from a globally routable address or network
space.
The above definitions still leave a lot to be interpreted. For this example, this document
redefines these terms by first defining "local address" and "global address." Keep in mind
that the terms "inside" and "outside" are NAT definitions. Interfaces on a NAT router are
defined as "inside" or "outside" with the NAT configuration commands, ip nat inside and
ip nat outside. Networks to which these interfaces connect can then be thought of as
"inside" networks or "outside" networks, respectively.
* Local address - A local address is any address that appears on the "inside" portion of
the network.
* Global address - A global address is any address that appears on the "outside" portion
of the network.

Front 142

Which protocol automates all of the following functions for hosts on a network: IP
configuration, IP addresses, subnet masks, default gateways, and DNS server
information?
A. CDP
B. SNMP
C. DHCP
D. ARP
E. DNS
F. None of the above

Back 142

Answer: C

Hint 142

Explanation:
DHCP uses the concept of the client making a request and the server supplying the IP
address to the client, plus other information such as the default gateway, subnet mask,
DNS IP address, and other information.
Incorrect Answers:
A. CDP is the Cisco Discovery Protocol. It is used by Cisco devices at the data link layer
to obtain information about their directly connected neighbors.
B. SNMP is the Simple Network Management Protocol. This is used for the maintenance,
management, and monitoring of network devices.
D. ARP is the Address Resolution Protocol, which is used to resolve layer 2 MAC
addresses to layer 3 IP addresses.
E. DNS is the Domain Name Service. It is used to resolve domain names (for example,
www. Certkiller .com) to IP addresses. The IP address location of primary and secondary
DNS resolver servers can be obtained for hosts using DHCP

Front 143

Which one of the following protocols uses both UDP and TCP ports for the
transport layer operation?
A. FTP
B. TFTP
C. SMTP
D. Telnet
E. DNS

Back 143

Answer: E

Hint 143

Explanation:
TCP and UDP must use port numbers to communicate with the upper layers. Port
numbers keep track of different conversations crossing the network simultaneously.
Originating-source port numbers are dynamically assigned by the source host, which will
be some number starting at 1024. 1023 and below are defined in RFC 1700, which
discusses what is called well-known port numbers.
Virtual circuits that do not use an application with a well-known port number are
assigned port numbers randomly chosen from within a specific range instead. These port
numbers identify the source and destination host in the TCP segment. Only DNS uses
both UDP and TCP port 53.

Front 144

Certkiller is using private IP addressing in their network. Which of the following IP
addresses is a private IP address? (Select all that apply)
A. 12.0.0.1
B. 168.172.19.39
C. 172.20.14.36
D. 172.33.194.30
E. 192.168.42.34
F. 11.11.11.1

Back 144

Answer: C, E

Hint 144

Explanation:
RFC 1918 Private Address Space:
Range of IP
Class of Networks
Number of Network
Addresses
A 1
10.0.0.0 to
10.255.255.255.255
B 16
172.16.0.0 to
172.31.255.255
C 256
192.168.0.0 to
192.168.255.255

Front 145

Certkiller is migrating to a private IP addressing scheme. Which of the following
describe the use of private IP addresses? (Choose two)
A. Addresses chosen by Certkiller .com to communicate with the Internet.
B. Addresses that cannot be routed through the public Internet.
C. Addresses that can be routed through the public Internet
D. A scheme to conserve public addresses.
E. Addresses licensed to enterprise or ISPs by an Internet registry organization

Back 145

Answer: B, D

Hint 145

Explanation:
Private IP address space has been allocated via RFC 1918. This means the addresses are
available for any use by anyone and therefore the same private IP addresses can be
reused. However they are defined as not routable on the public Internet. They are used
extensively in private networks due to the shortage of publicly registered IP address
space and therefore network address translation is required to connect those networks to
the Internet

Front 146

Certkiller is using IP addressing according to RFC 1918. Which three address
ranges are used for internal private address blocks as defined by RFC 1918?
(Choose all that apply)
A. 0.0.0.0 to 255.255.255
B. 10.0.0.0 to 10.255.255.255
C. 172.16.0.0 to 172.16.255.255
D. 172.16.0.0 to 172.31.255.255
E. 127.0.0.0. to 127.255.255.255
F. 192.168.0.0 to 192.168.255.255
G. 224.0.0.0 to 239.255.255.255

Back 146

Answer: B, D, F

Hint 146

Explanation:
RFC 1918 defines three different IP address ranges as private, meaning that they can be
used by any private network for internal use, and these ranges are not to be used in the
Internet. The class A private range is 10.0.0.0 to 10.255.255.255. The class B address
range is 172.16.0.0 to 172.31.255.255. The class C private IP address range is
192.168.0.0 to 192.168.255.255.
Incorrect Answers:
A. The 0.0.0.0 network address is invalid and can not be used.
C. The correct address range is 172.16.X.X through 172.31.X.X
E. The 127.0.0.1 address is reserved for the internal loopback IP address, but the entire
127.X.X.X range is not defined in RFC 1918 as a private address range for networks.
G. This address range describes the class D multicast address range

Front 147

Certkiller needs to ensure their IP network can be reached from the Internet. Which
of the following host addresses are members of networks that can be routed across
the public Internet? (Choose three.)
A. 10.172.13.65
B. 172.16.223.125
C. 172.64.12.29
D. 192.168.23.252
E. 198.234.12.95
F. 212.193.48.254

Back 147

Answer: C, E, F

Hint 147

Explanation:
In Internet terminology, a private network is a network that uses RFC 1918 IP address
space. Computers may be allocated addresses from this address space when it's necessary
for them to communicate with other computing devices on an internal (non-Internet)
network but not directly with the Internet.
Three blocks of IP addresses are reserved for private use and are not routed over the
Internet. Companies can assign these addresses to nodes on their private LANs at any
time without conflict.
CIDR
From To Representation
10.0.0.0 10.255.255.255 10/8
172.16.0.0 172.31.255.255 172.16/12
192.168.0.0 192.168.255.255 192.168/16

Front 148

Certkiller has 25 computers and decides to connect the network to the Internet.
Certkiller would like for all of the computers to have access to the Internet at the
same time, but Certkiller only has four usable publicly routable IP addresses.
What should be configured on the router so that all computers can connect to the
Internet simultaneously?
A. Static NAT
B. Global NAT
C. Dynamic NAT
D. Static NAT with ACLs
E. Dynamic NAT with overload

Back 148

Answer: E

Hint 148

Explanation:
NAT overload, also called many to one NAT or Port Address Translation (PAT) allows
for many IP hosts to share a single IP address when connecting to the outside. In this
case, the use of dynamic NAT with overloading will allow for the 25 hosts to use an IP
address from the NAT pool, which will contain the 4 public IP addresses.

Front 149

A Certkiller router has been configured with the following command:
IP nat pool nat-test 192.168.6.10 192.168.6.20 netmask 255.255.255.0
This is an example of what type of NAT?
A. Static NAT
B. Dynamic NAT
C. Dynamic NAT with overload
D. Port Address Translation
E. None of the above

Back 149

Answer: B

Hint 149

Explanation:
The configuration statement in this example is used to define a pool of IP addresses to be
used for dynamic NAT translations.
Incorrect Answers:
A. Static NAT is used for 1 to 1 translation entries, using the "static" configuration
keyword. In this example a range of addresses are being defined for the use in a pool.
C, D. With NAT overload, also known as Port Address Translation (PAT), the keyword
"overload" is added at the end of the configuration statement

Front 150

The administrator of the Certkiller network needs to ensure that a web server in
their network is accessible from the Internet. Since the network uses private
addressing, this requires an IP-to-registered-address mapping. The following
command is entered on the router:
Certkiller 1(config)# ip nat inside source static 192.168.2.1 198.18.1.254
After unsuccessful results from a ping to the Internet, the administrator issues the
show ip nat translations command and the output is blank. What could be the
problem with the NAT configuration for this mapping?
A. The keyword overload is missing from the command.
B. The administrator needs to define a NAT pool first.
C. An access list must be defined to create static NAT translations.
D. The interfaces need to be configured for NAT.

Back 150

Answer: D

Hint 150

Explanation:
After configuring the static NAT administrator should configure the NAT on interface in
order to define which interfaces are on the outside and which are on the inside:
Example:
interface s0
ip nat outside àBecause s0 interface is connected to ISP
interface e0
ip nat inside à Because e0 interface is connected to Local LAN.
Incorrect Answers:
A, B, C: These are all tasks that need to be configured when performing many to one
NAT, also known as Port Address Translation (PAT). In this example, we are specifying
a static 1-1 NAT entry.

Front 151

You are a systems administrator and you are about to assign static IP addresses to
various servers on your network. For the network 192.168.20.24/29 the router is
assigned to the first usable host address, while the last usable host address goes to
your Sales server. Which one of the following commands would you enter into the
IP properties box of the sales server?
A. IP address: 192.168.20.14 Subnet Mask: 255.255.255.248 Default Gateway:
192.168.20.9
B. IP address: 192.168.20.254 Subnet Mask: 255.255.255.0 Default Gateway:
192.168.20.1
C. IP address: 192.168.20.30 Subnet Mask 255.255.255.248 Default Gateway:
192.168.20.25
D. IP address: 192.168.20.30 Subnet Mask 255.255.255.240 Default Gateway:
192.168.20.17
E. IP address: 192.168.20.30 Subnet Mask 255.255.255.240 Default Gateway:
192.168.20.25

Back 151

Answer: C

Hint 151

Explanation
A subnet mask uses 29 bits. This means that it uses 5 bits in the 4th octet. This equates to
255.255.255.248. This network has 3 bits for hosts. Using the 2n-2 formula (23-2) in this
case), we are left with 6 (2*2*2 - 2 = 6) host addresses. 192.168.20.24 is the network
address. Therefore the next address (192.168.20.25) would be the first host address. This
address must be assigned to the router, which serves as the gateway for the network. The
last available host address would be 192.168.20.30 (192.168.20.24+6). This address is
assigned to the server. The broadcast address is 192.168.20.31.

Front 152

You've been assigned a single Class C address. From this, you need 8 subnets, and
your subnet mask is 255.255.255.224. Which one of the following configuration
commands would you have to use before you begin?
A. Router(config)# ip classless
B. Router(config)# ip subnet-zero
C. Router(config)# ip version 6
D. Router(config)# no ip classful
E. Router(config)# ip unnumbered
F. Router(config)# ip all-nets

Back 152

Answer: B

Hint 152

Explanation:
To get 8 subnets from a class C address, and a mask of 255.255.255.224 use the
reserved subnet space. To do this, you need the command 'ip subnet-zero.' This will
allow the router to use the very first subnet, which is normally reserved and unused
as the network address.Prior to Cisco IOS(r) Software Release 12.0, Cisco routers,
by default, did not allow an IP address belonging to subnet zero to be configured on
an interface. However, if a network engineer working with a Cisco IOS software
release older than 12.0 finds it safe to use subnet zero, the ip subnet-zero command
in the global configuration mode can be used to overcome this restriction. As of
Cisco IOS Software Release 12.0, Cisco routers now have ip subnet-zero enabled by
default, but if the network engineer feels that it is unsafe to use subnet zero, the no
ip subnet-zero command can be used to restrict the use of subnet zero addresses.
In versions prior to Cisco IOS Software Release 8.3, the service subnet-zero command
was used.
It should be noted that even though it was discouraged, the entire address space including
subnet zero and the all-ones subnet have always been usable. The use of the all-ones
subnet was explicitly allowed and the use of subnet zero is explicitly allowed since Cisco
IOS Software Release 12.0. Even prior to Cisco IOS Software Release 12.0, subnet zero
could be used by entering the ip subnet-zero global configuration command.
On the issue of using subnet zero and the all-ones subnet, RFC 1878 states, "This practice
(of excluding all-zeros and all-ones subnets) is obsolete. Modern software will be able to
utilize all definable networks." Today, the use of subnet zero and the all-ones subnet is
generally accepted and most vendors support their use. However, on certain networks,
particularly the ones using legacy software, the use of subnet zero and the all-ones subnet
can lead to problems

Front 153

Which of the following addresses can be assigned to a host when using a subnet
mask of 255.255.254.0? (Select three)
A. 113.10.4.0
B. 186.54.3.0
C. 175.33.3.255
D. 26.35.2.255
E. 152.135.7.0
F. 17.35.36.0

Back 153

Answer: B, D, E

Hint 153

These are all valid host IP addresses within the /23 subnet.
Incorrect Answers:
A. This is the network address for the 113.10.4.0/23 subnet.
C. This is the broadcast address for the 175.33.2.0/23 subnet.
F. This is the network address for the 17.35.36.0/23 subnet.

Front 154

Which command on router Certkiller A will assign the last usable IP address from
the 192.168.32.128/28 subnetwork to a router interface?
A. Certkiller A(config-if)# ip address 192.168.32.142 255.255.255.240
B. Certkiller A(config-if)# ip address 192.168.32.143 255.255.255.240
C. Certkiller A(config-if)# ip address 192.168.32.158 255.255.255.240
D. Certkiller A(config-if)# ip address 192.168.32.145 255.255.255.240
E. Certkiller A(config-if)# ip address 192.168.32.144 255.255.255.240
F. Certkiller A(config-if)# ip address 192.168.32.158 255.255.255.240
G. None of the above

Back 154

Answer: A

Hint 154

Explanation:
The last usable IP address would be 128 + (16-2) = 142 because only the last 4 bits of the
last octet are used for host addressing.

Front 155

Certkiller is opening a new branch office. Assuming a subnet mask of 255.255.248.0,
which three addresses are valid host IP addresses that could be used in this office?
(Choose three.)
A. 172.16.20.0
B. 172.16.24.0
C. 172.16.8.0
D. 172.16.16.0
E. 172.16.31.0
F. 172.16.9.0

Back 155

Answer: A, E, F

Hint 155

Explanation:
For the 255.255.248.0 subnet mask the following is true.
1. 2-2=30 subnets
2. 2-2=2,046 hosts per subnet
3. 256-248=8.0, 16.0, 24.0, 32.0, 40.0, 48.0, 56.0, 64.0, etc.
4. Broadcast for the 8.0 subnet is 15.255. Broadcast for the 16.0 subnet is 23.255, etc.
5. The valid hosts are:
Subnet 8.0 16.0 24.0 32.0 40.0 48.0 56.0 64.0
first host 8.1 16.1 24.1 32.1 40.1 48.1 56.1 64.1
last host 15.254 23.254 31.254 39.254 47.254 55.254 63.254 71.254
t15.255 23.255 31.255 39.255 47.255 55.255 63.255 71.255
broadcas
Reference: http://articles.techrepublic.com.com/5100-6350-5033673.html

Front 156

While troubleshooting a connectivity issue from a PC you obtain the following
information:
Local PC IP address: 190.0.3.35/24
Default Gateway: 190.0.3.1
Remote Server: 190.0.5.250/24
You then conduct the following tests from the local PC:
Ping 127.0.0.1 - Unsuccessful
Ping 190.0.3.35 - Successful
Ping 190.0.3.1 - Unsuccessful
Ping 190.0.5.250 - Unsuccessful
What is the underlying cause of this problem?
A. TCP/IP not correctly installed
B. Local physical layer problem
C. NIC not functioning
D. Remote physical layer problem
E. None of the above

Back 156

Answer: A

Hint 156

Explanation:
Every Windows based PC uses the 127.0.0.1 as the local loopback IP address. Every PC
will respond to this local IP address if the TCP/IP stack is correctly installed and running
on the machine. If you cannot ping the loopback address of 127.0.0.1, then something is
wrong with the TCP/IP protocol stack

Front 157

Router CK1 receives information about network 192.168.111.0/24 from multiple
sources. What will CK1 consider the most reliable information about the path to
that network?
A. An OSPF update for network 192.168.111.0/16
B. A static route to network 192168.1111.0/24
C. A Directly connected interface with an address of 192.168.1111.254/24
D. A RIP update for network 192.168.1111.0/24
E. A Default route with a next hop address of 192.168.1111.1
F. A static route to network 192.168.1111.0/24 with a local serial interface configured as
the next hop
G. None of the above

Back 157

Answer: C

Front 158

Router CK1 has just received a packet and needs to route it. What two actions must
this router take in order to route incoming packets? (Choose two)
A. Inspect the routing table to select the best path to the destination network addresses.
B. Validate sources of routing information.
C. Inspect the ARP table to verify a legitimate source MAC address for each packet.
D. Identify the destination network address of each packet.
E. Verify the receipt of routed packets by the next hop router.
F. Identify the source network address of each packet.

Back 158

Answer: A, D

Hint 158

Explanation:
The router decides how to forward an incoming packet by finding the routes that "match"
the destination address of the packet, and then forwarding it according to the most
narrowly applicable one. A packet matches a route in the following way: a packet has
(among other things) a destination address in its header, a route contains either a network
or a host address, a network mask (netmask), and instructions on how to forward a packet
using the route. The packet matches the route if its destination address is part of the
address subspace defined by the network address or exactly matches the host address of
the route. A route is more narrowly applicable than another if the address subspace
defined by its network address contains fewer actual addresses than the other, which is
indicated by the netmask. An entry with a host address, rather than a network address, is
the narrowest kind

Front 159

During startup, router CK1 displays the following error message:
boot: cannot open "flash:"
What will CK1 do next?
A. It will attempt to locate the configuration file from a TFTP server. If this fails, it will
initiate the setup dialog.
B. It will attempt to locate the IOS from a TFTP server. If this fails, it will load a limited
IOS from ROM.
C. It will attempt to locate the configuration file from a TFTP server. If this fails, it will
load a limited configuration from ROM.
D. Because of damaged flash memory, the router will fail the POST.
E. It will attempt to locate the IOS from a TFTP server. If this fails, it will initiate the
setup dialog.
F. None of the above

Back 159

Answer: B

Hint 159

Explanation:
The boot sequence of a Cisco router is shown below:
Booting up the router and locating the Cisco IOS
1. POST (power on self test)
2. Bootstrap code executed
3. Check Configuration Register value (NVRAM) which can be modified using the
config-register command
0 = ROM Monitor mode
1 = ROM IOS
2 - 15 = startup-config in NVRAM
4. Startup-config file: Check for boot system commands (NVRAM)
If boot system commands in startup-config
a. Run boot system commands in order they appear in startup-config to locate the IOS
b. [If boot system commands fail, use default fallback sequence to locate the IOS (Flash,
TFTP, ROM)?]
If no boot system commands in startup-config use the default fallback sequence in
locating the IOS:
a. Flash (sequential)
b. TFTP server (netboot)
c. ROM (partial IOS) or keep retrying TFTP depending upon router model
5. If IOS is loaded, but there is no startup-config file, the router will use the default
fallback sequence for locating the IOS and then it will enter setup mode or the setup
dialogue.
6. If no IOS can be loaded, the router will get the partial IOS version from ROM
Reference: http://www.svrops.com/svrops/documents/ciscoboot.htm

Front 160

After logging into a router and typing in a few show commands, you press the up
arrow key. What will this do?
A. It will recall the previous command line
B. It will move the cursor one line up
C. It will redisplay the current command line
D. It will capitalize the command line
E. None of the above

Back 160

Answer: A

Hint 160

Explanation:
The up arrow key is used to recall the previous command line entry. The commands that
were entered previously can be displayed by repeatedly pressing the up arrow key, or by
entering the "show history" command

Front 161

After working on a router, some problems arise and you wish to view the commands
that you recently entered. Which IOS command opens the history buffer and
displays the most recently entered commands?
A. Show history
B. Show buffers
C. Show typed commands
D. Show terminal buffer
E. Show command
F. None of the above

Back 161

Answer: A

Hint 161

Explanation:
The router will buffer previously entered commands. By default, the "show history"
command will display the previous ten commands that were entered. To see the contents
of the buffer you enter the show history command.
Incorrect Answers:
B. This command will show the memory buffer information
C, D. These are invalid commands

Front 162

You have just purchased a brand new router and wish to have the router prompt
you through the initial configuration commands. Which router mode does this
describe?
A. ROM Monitor mode
B. SETUP mode
C. Autoflash mode
D. RXBOOT mode
E. None of the above

Back 162

Answer: B

Hint 162

Explanation:
Setup mode is a convenient mode that walks you through the setup procedure by
prompting you with specific questions and options one by one

Front 163

After working all night and successfully configuring a Cisco router for the Certkiller
network you save your changes on the startup config, reboot the router, and go out
for a cigarette. When you return, none of your changes are active and the router
boots to the initial configuration mode! Which of the choices below indicates the
source of your problem?
A. Hardware failure in NVRAM prevents the router from loading the config
B. Startup-config in flash is corrupt and cannot be analyzed
C. Router configuration-register set to bypass startup configuration
D. Startup-config in NVRAM is corrupt and cannot be analyzed
E. None of the above

Back 163

Answer: C

Hint 163

Explanation:
The default configuration-register setting of 0x2102 loads the IOS from flash and the
configuration from NVRAM.
However, for password recovery, you can set the register to 0x2142 and the
startup-config file in NVRAM will be bypassed. The problem described here is that the
config register was not changed back to 0x2102 before the router was rebooted, so the
active configuration is bypassed. Simply setting the config register back to 0x2102 will
fix this problem.
Incorrect Answers:
A, B, D. All of these describe hardware or software errors. In the event that this is the
problem, errors will be generated and the router will fail to boot properly. In these cases,
the router will not return to the initial startup configuration

Front 164

While working in setup mode, a configuration line is typed incorrectly. What should
you do to exit setup mode, without executing or saving any of the mistakes you
made? (Select two answer choices)
A. Type exit at the setup dialog.
B. Type close at the setup dialog.
C. Press the Ctrl-C key combination.
D. Press the Ctrl-X key combination.
E. Issue the copy startup-config command.
F. Issue the 'write e" command.
G. Issue the "write mem" command

Back 164

Answer: C

Hint 164

Explanation:
Here is the partial output from new router while it boots up:
At any point you may enter a question mark '?' for help.
Refer to the 'Getting Started' Guide for additional help.
Use ctrl-c to abort configuration dialog at any prompt.
Incorrect Answers:
A. The Exit command can not be used during setup mode.
B. This is an invalid command
E. This command is used to save the conf iguration stored on NVRAM to a location.
F. This will have the effect of erasing the running configuration, and setting the router
configuration back to the factory default settings.
G. This is an old command that is still supported on the latest Cisco IOS. It is short for
"write memory" and has the same effect as the "copy running-config startup-config"
command

Front 165

You are a senior network administrator at Certkiller , and while performing the
password recovery procedure on your 2500 series Cisco router, you type in the
following command:
o/r0x2142
What is the purpose of this command?
A. It is used to restart the router.
B. It is used to bypass the configuration in NVRAM.
C. It is used to enter ROM Monitor mode.
D. It is used to view the lost password.
E. It is used to save the changes to the configuration

Back 165

Answer: B

Hint 165

Explanation:
Theo/r 0x2142 command changes the value of config-register to 2142 in a Cisco 2500
series router, so that the Router ignores the NVRAM contents and reverts to the initial
setup configuration mode when it boots

Front 166

Why might the Certkiller network administrator set the configuration register to
0x2142 on a 2600 series Cisco router?
A. To boot the IOS from ROM
B. To reset the console password

Back 166

Answer: B

Hint 166

Explanation:
About 99 percent of the time someone uses a config-register, it's more than likely
because of a lost router password. The two config-registers for recovering passwords are
0x2102 and 0x2142.
The first config-register, 0x2102, is the normal config-register if you boot the router from
internal Flash. You can see this config-register by using the show version command.
In this output, you'll notice the last line says, "Configuration register is 0x2102." This is
normal.
But let's say you forgot the router's password. To recover this password (as long as it's
unencrypted), boot the router and bypass the startup-config using config-register 0x2142;
you should then be able to see the password in the startup-config. You can use the same
method for encrypted passwords, but you'll need to overwrite the original password with
a new one. To change the configuration register, enter the following:
Router(config)# config-register 0x2142
This will instruct the router to bypass the configuration and boot up as if it were a brand
new router using factory default settings

Front 167

After making some network changes you power off and then power on your Cisco
router named CK1 . What sequence of events occurs when CK1 is powered up?
A. Perform POST, locate configuration statements, apply configuration statements, locate
Cisco IOS software, and load Cisco IOS software.
B. Locate Cisco IOS software, load Cisco IOS software, locate configuration statements,
apply configuration statements, and perform POST.
C. Test software routines, POST, load configuration files, load Cisco IOS software, test
Cisco IOS software.
D. Perform POST, locate Cisco IOS software, load the Cisco IOS software, locate
configuration statements, and apply configuration statements.
E. Load and test IOS, load configuration files, test software routines, POST.
F. None of the above

Back 167

Answer: D

Hint 167

Explanation:
Upon initial start up, Cisco routers perform the following steps in order:
1. The router performs a power-on self-test (POST) to discover and verify the hardware.
2. The router loads and runs bootstrap code from ROM
3. The router finds the IOS or other software and loads it.
4. The router finds the configuration file and loads it into running config

Front 168

You are the network administrator at Certkiller . You need to perform password
recovery on Router CK1 . What must you modify in the password recovery process?
(Choose two.)
A. Configuration register
B. NVRAM
C. Boot flash
D. CMOS
E. Flash

Back 168

Answer: A, B

Hint 168

Explanation:
Recovering a Lost Password
This section describes how to recover a lost enable password and how to enter a new
enable secret password.
Password recovery consists of the following major processes:
Determining the Configuration Register Value
1. With this process, you determine the configuration of the router, so that you may
restore the configuration after the password is recovered.
Resetting the Router
1. With this process, you reconfigure the router to its initial startup configuration. You
then display the enable password, if one is used.
Resetting the Password
1. If you are using an enable secret password, you enter a new password with this
process. You then restore the router to its prior configuration.
Resetting the Configuration Register Value
1. If you are using an enable password, you use this process to restore the router to its
prior configuration

Front 169

How can a Certkiller administrator determine if a router has been configured when
it is first powered up?
A. A configured router prompts for a password
B. A configured router goes to the privileged mode prompt
C. An un configured router goes into the setup dialog
D. An un configured router goes to the enable mode prompt

Back 169

Answer: C

Hint 169

Explanation:
If a non-configured router is started, then it goes into setup mode and ask for the
minimum configuration parameters (hostname, IP address to interfaces, enable password,
etc). If the router is already configured it boots by implementing the saved startup-config

Front 170

What will cause a Certkiller router to enter setup mode? (Choose two)
A. The configuration file is missing in NVRAM.
B. The configuration register is set to 0x2100.
C. Boot system commands are misconfigured in the running-configuration.
D. The setup command was issued from the privileged mode prompt.
E. The IOS is missing.
F. The IOS is corrupt

Back 170

Answer: A, D

Hint 170

Explanation:
When router boots up, it checks the valid configuration into NVRAM and tries to load
the configuration. If there is not configuration router automatically goes into setup
dialog. From setup dialog, you able to configuration the basic configuration. As well you
can run the setup command manually from privileged mode using the setup command.

Front 171

What is the default configuration register setting on most Cisco routers?
A. 0x2104
B. 0x2012
C. 0x2210
D. 0x2102
E. 0x2142
F. None of the above

Back 171

Answer: D

Hint 171

Explanation:
About 99 percent of the time someone uses a config-register, it's more than likely
because of a lost router password. Normally, the two config-registers for recovering
passwords are 0x2102 and 0x2142.
The first config-register, 0x2102, is the normal config-register if you boot the router from
internal Flash. You can see this config-register by using the show version command.
In this output, you'll notice the last line says, "Configuration register is 0x2102." This is
normal.

Front 172

During the boot sequence, a Certkiller 2800 series router needs to locate and load an
operating system. What is the default order the router uses to find an operating
system?
A. ROM, TFTP server, Flash
B. Flash, TFTP server, ROM
C. Flash, NVRAM, TFTP server
D. Flash, ROM, TFTP server
E. Flash, TFTP server, RAM

Back 172

Answer: B

Hint 172

Explanation:
Booting up the Router:
Cisco routers can boot Cisco IOS software from these locations
1. Flash memory
2. TFTP server
3. ROM (not full Cisco IOS)
Multiple source options provide flexibility and fallback alternatives.
Reference: http://www.svrops.com/svrops/documents/ciscoboot.htm

Front 173

What will a new Certkiller router do during startup if a configuration file is not
located in NVRAM?
A. It will search for the configuration file in the locations specified by boot system
commands.
B. It will search for the configuration file in flash and if no configuration file is found
there, it will enter the setup dialog.
C. It will search for the configuration file on a TFTP server and if no configuration file is
found there, it will enter the setup dialog.
D. It will search for the configuration file in flash and if no configuration file is found
there, it will load a limited configuration file from ROM.
E. It will search for the configuration file on a TFTP server and if no configuration file is
found there, it will load a limited configuration file from ROM.

Back 173

Answer: C

Hint 173

Explanation:
When a router boots and is able to locate the IOS it begins to load the configuration file.
The configuration file, saved in NVRAM, is loaded into main memory and executed one
line at a time. These configuration commands start routing processes, supply addresses
for interfaces, and set media characteristics.
If no configuration file exists in NVRAM, the router attempts a network boot and sends a
broadcast request for the file on a TFTP server. If this is also not found, the operating
system executes a question-driven initial configuration routine called the system
configuration dialog

Front 174

A Certkiller router boots up in ROMMON mode. What is ROM Monitor
(ROMMON)?
A. A memory component for storing the saved configuration file
B. A memory management tool
C. An operating system used for hardware troubleshooting and for password recovery
D. Temporary storage space for the router operating files
E. The source of the primary Cisco IOS software image
F. None of the above

Back 174

Answer: C

Hint 174

Explanation:
The ROM Monitor is a very limited code set that enables you to perform elementary
functions to manually get the router or switch back to a functioning state. You can
perform low-level diagnostics and even copy a new IOS file to the Cisco device over the
console port. It is also used after the break sequence is issued during bootup for password
recovery use

Front 175

Which type of cable should be used to make a connection between the Fa0/0 port on
a router and the Fa0/0 port switch?
A. Rollover cable
B. Console cable
C. Crossover cable
D. Straight-through cable
E. Serial cable

Back 175

Answer: D

Front 176

You are trying to connect directly into the LAN port of a Certkiller router. You
want to telnet to the local Cisco router using TCP/IP but cannot create a session.
What should you do to resolve the problem?
A. Use a straight-through cable to connect your computer's COM port to the router's
console port.
B. Use a crossover cable to connect your computer's COM port to the router's console
port.
C. Use a straight-through cable to connect your computer's COM port to the router's
Ethernet port.
D. Use a crossover cable to connect your computer's Ethernet port to the router's Ethernet
port.
E. Use a rollover cable to connect your computer's Ethernet port to the router's Ethernet
port.
F. Use a straight-through cable to connect your computer's Ethernet port to the router's
Ethernet port.
G. None of the above

Back 176

Answer: D

Hint 176

connections.
F. Straight through cables are used for connections into a switch or hub from the PC. It
will not work for direct Ethernet connections into the router.

Front 177

RIP version 2 is being used as the routing protocol within the Certkiller network.
What does RIP version 2 use to prevent routing loops? (Choose two)
A. CIDR
B. Split horizon
C. Authentication
D. Classless masking
E. Hold-down timers
F. Multicast routing updates
G. Path Vectoring

Back 177

Answer: B, E

Hint 177

Explanation:
Distance Vector routing protocols employ the split horizon mechanism to reduce the
possibility of routing loops. Split horizon blocks information about routes from being
advertised by a router out of any interface from which that information originated.
RIP versions 1 and 2 also use the concept of hold timers. When a destination has become
unreachable (or the metric has increased enough to cause poisoning), the destination goes
into "holddown". During this state, no new path will be accepted for the same destination
for this amount of time. The hold time indicates how long this state should last.
Incorrect Answers:
A, C, D, F. Although these are all features and functions of RIP version 2, they are not
mechanisms used to prevent routing loops.
G. Path Vectoring is a concept used by BGP routers. RIP version 1 and 2 are considered
to be distance vector routing protocols

Front 178

The Certkiller WAN is migrating from RIPv1 to RIPv2. Which three statements are
correct about RIP version 2? (Choose three)
A. It uses broadcast for its routing updates
B. It supports authentication
C. It is a classless routing protocol
D. It has a lower default administrative distance than RIP version 1
E. It has the same maximum hop count as version 1
F. It does not send the subnet mask un updates

Back 178

Answer: B, C, E

Front 179

Which one of the following commands would you enter to terminate a VTY line
session?
A. close
B. disable
C. disconnect
D. suspend
E. exit
F. None of the above

Back 179

Answer: E

Hint 179

Explanation:
A VTY line is a telnet session. To end a telnet session from a remote device, enter the
exit or logout command.
Incorrect Answers:
A, B, C, D. These are all invalid commands

Front 180

You work as a network engineer at Certkiller .com. You are required to allow
establishment of a Telnet session with a router Certkiller C.
Which set command must be configured?
A. Certkiller C(config)# line console 0
Certkiller C(config-line)# enable password Certkiller
B. Certkiller C(config)# line console 0
Certkiller C(config-line)# enable secret Certkiller
Certkiller C(config-line)# login
C. Certkiller C(config)# line console 0
Certkiller C(config-line)# password Certkiller
Certkiller C(config-line)# login
D. Certkiller C(config)# line vty 0
Certkiller C(config-line)# enable password Certkiller
E. Certkiller C(config)# line vty 0
Certkiller C(config-line)# enable secret Certkiller
Certkiller C(config-line)# login
F. Certkiller C(config)# line vty 0
Certkiller C(config-line)# password Certkiller
Certkiller C(config-line)# login

Back 180

Answer: F

Hint 180

Explanation:
CLI Password Configuration:
Access From Password Type Configuration
Console Console password Line console 0 Login
Password Certkiller
Auxiliary Auxiliary password Line aux 0 Login
Password ckrules
Telnet Vty password Line vty 0 4 Login
Password
Certkillerrules

Front 181

Which sequence of actions will allow telnet traffic from a Certkiller user's PC to a
router using TCP/IP?
A. Connect the PC's COM port to the router's console port using a straight-through cable.
B. Connect the PC's COM port to the router's console port using a crossover cable.
C. Connect the PC's COM port to the router's Ethernet port using a straight-through
cable.
D. Connect the PC's Ethernet port to the router's Ethernet port using a crossover cable.
E. Connect the PC's Ethernet port to the router's Ethernet port using a rollover cable.
F. Connect the PC's Ethernet port to the router's Ethernet port using a straight-through
cable.
G. None of the above

Back 181

Answer: D

Hint 181

Explanation:
A crossover cable is used to directly connect a switch to a switch, a hub to a hub, a host
to a host, or a host's Ethernet port to a router's Ethernet interface. If your Router's
interface is configured with IP addressing and telnet service is enabled you can log
through the telnet program into your router.
Incorrect Answers:
A, B, C: The COM port is used for direct terminal connections to a router, via the use of
terminal emulation programs such as HyperTerminal.
E: A rollover cable is used to connect via a console connection.
F: A straight through cable would be used if there was a LAN switch or a hub in place,
but when connecting to the router directly from a PC a cross over cable should be used.

Front 182

You are given a PC, a router, and a cable. Select the correct combination that will
allow you to log into router CK1 locally using a terminal emulation program such as
HyperTerminal.
A. Connect the PC's COM port to the router's console port using a straight-through cable.
B. Connect the PC's COM port to the router's console port using a rollover cable.
C. Connect the PC's COM port to the router's Ethernet port using a straight-through
cable.
D. Connect the PC's Ethernet port to the router's Ethernet port using a rollover cable.
E. Connect the PC's Ethernet port to the router's Ethernet port using a straight- through
cable.
F. None of the above

Back 182

Answer: B

Hint 182

Explanation:
To connect the Router in Console port to configure using HyperTerminal, you required
the Rollover Cable, which connects the PC's COM port to the router's Console port.
Incorrect Answers:
A, C, E: Straight Cables are used for: Host to switch, Switch to Router.
D: Rollover cables are used for Console/COM connections, not for IP traffic over the
Ethernet ports.

Front 183

Which router console commands shown below are used to manage telnet sessions to
other routers? (Select three)
A. Certkiller D# disconnect 3
B. Certkiller D# exit session 2
C. Certkiller D# kill connection 1
D. Certkiller D# show sessions
E. Certkiller D# show connection all
F. Certkiller D# resume 4

Back 183

Answer: A, D, F

Front 184

You need to make changes to a new Certkiller router. By which prompt is the global
configuration mode on this router identified?
A. Router(config-line)#
B. Router(config-router)#
C. Router#
D. Router(config)#
E. Router>
F. Router(config-if)#
G. None of the above

Back 184

Answer: D

Hint 184

Explanation:
There are many different configuration modes. Each of these makes changes to the
device configuration. To ensure that those configuration changes are not lost if the router
reboots, you must copy the running configuration to the startup configuration. The type
and number of configuration submodes depends on the type of router, the Cisco IOS
version, and the components installed on the router:
- Global configuration mode- The command for accessing the global configuration mode
is configure terminal. In the global configuration mode, the router continues to display its
host name followed by (config) and the # symbol:
RouterA#configure terminal
RouterA(config)#
The global configuration mode is where you can make "global" changes to the
configuration of the router. A common example of a global configuration is the creation
of an access list. From the global configuration mode, you can move to a position that
enables you to configure specific components of the router, such as the router interfaces;
virtual private network (VPN) components (sump, crypto, and so on); CLI connections
(line); authentication, authorization, and accounting (AAA) server groups; and many
more. To exit to the privileged global configuration mode, use the key combination
Ctrl-Z or type the command "end."

Front 185

You need to configure a new Cisco router for remote access on the Certkiller
network. How many simultaneous telnet sessions does this Cisco router support by
default?
A. 4
B. 2
C. 5
D. 1
E. 6
F. 0

Back 185

Answer: C

Hint 185

Explanation:
Telnet sessions use virtual terminal sessions, which are configured under the "line vty"
portion of the configuration. There are 5 total vty sessions that can be configured,
numbered 0-4.

Front 186

Which of the following commands displays the configurable parameters and
statistics of all interfaces on a router?
A. show interfaces
B. show processes
C. show running-config
D. show versions
E. show startup-config

Back 186

Answer: A

Hint 186

Explanation:
Use the show interfaces EXEC command to display statistics for all interfaces
configured on the router or access server. The resulting output varies, depending on the
network for which an interface has been configured.
The following is an example from theshow interfaces command. Because your display
will depend on the type and number of interface cards in your router or access server,
only a portion of the display is shown.
CK1 #showinterfaces
Ethernet0isup,lineprotocolisup
HardwareisMCIEthernet,addressis0000.0c00.750c(bia0000.0c00.750c)
Internetaddressis131.108.28.8,subnetmaskis255.255.255.0
MTU1500bytes,BW10000Kbit,DLY100000usec,rely255/255,load1/255
EncapsulationARPA,loopbacknotset,keepaliveset(10sec)
ARPtype:ARPA,ARPTimeout4:00:00
Lastinput0:00:00,output0:00:00,outputhangnever
Lastclearingof"showinterface"counters0:00:00
Outputqueue0/40,0drops;inputqueue0/75,0drops
Fiveminuteinputrate0bits/sec,0packets/sec
Fiveminuteoutputrate2000bits/sec,4packets/sec
1127576packetsinput,447251251bytes,0nobuffer
Received354125broadcasts,0runts,0giants,57186*throttles
0inputerrors,0CRC,0frame,0overrun,0ignored,0abort
5332142packetsoutput,496316039bytes,0under runs
0outputerrors,432collisions,0interfaceresets,0restarts
Reference:
http://www.cisco.com/univercd/cc/td/doc/product/software/ios120/12cgcr/inter_r/irshowin.htm

Front 187

An administrator issues the show ip interface s0/0 command and the output displays
that interface Serial0/0 is up, line protocol is up
What does "line protocol is up" specifically indicate about the interface?
A. The cable is attached properly.
B. CDP has discovered the connected device.
C. Keepalives are being received on the interface.
D. A carrier detect signal has been received from the connected device.
E. IP is correctly configured on the interface

Back 187

Answer: C

Hint 187

Explanation:
Serial 0/0 is up, line protocol is up is the proper status line condition.
Line serial0/0 is up: This statement represents that the physical connection is good.
Line protocol is up: This represents that the data link layer is OK, meaning that layer 2
keepalives are being received on the interface.
When the line protocol goes down, a possible problem is keep-alive not being sent by
remote router.

Front 188

You need to configure the interfaces on a new Certkiller router, but first you need to
enter the global configuration mode. Which command is used on router Certkiller 3
to reach this mode?
A. Certkiller 3# router
B. Certkiller 3# setup
C. Certkiller 3# interface
D. Certkiller 3> enable
E. Certkiller 3# configure terminal

Back 188

Answer: E

Hint 188

Explanation:
Global configuration mode is the mode that allows you to configure the router and it
takes effect immediately. You can enter into the global configuration mode using
"configure terminal" command.
Interface configuration mode allows you to configure the interface on a particular
interface such as setting the IP address, setting bandwidth, clock rate, encapsulation type,
duplex, speed, etc. Use the "interface interface-name" command to enter into the
interface configuration mode

Front 189

Regarding the extended ping command; which of the statements below are true?
(Select all valid answer choices)
A. The extended ping command is supported from user EXEC mode.
B. The extended ping command is available from privileged EXEC mode.
C. With the extended ping command you can specify the TCP and UDP port to be
pinged
D. With the extended ping command you can specify the timeout value.
E. With the extended ping command you can specify the datagram size

Back 189

Answer: B, D, E

Hint 189

Explanation:
The extended ping command works only at the privileged EXEC command line.
Some of the extended ping command values include the datagram size and timeout value
as shown:
Datagram size [100]: Size of the ping packet (in bytes). Default: 100 bytes.
Timeout in seconds [2]:
Timeout interval. Default: 2 (seconds). The ping is declared successful only if the ECHO
REPLY packet is received before this time interval.
Incorrect Answers:
A. Regular pings are available in both user and privileged mode, but not extended pings.
C. Ports can not be specified.

Front 190

When you use the ping command to send ICMP messages across a network, what's
the most common request/reply pair you'll see? (Select one answer choice)
A. Echo request and Echo reply
B. ICMP hold and ICMP send
C. ICMP request and ICMP reply
D. Echo off and Echo on
E. None of the above

Back 190

Answer: A

Hint 190

Explanation:
The ICMP protocol uses Echo request and Echo reply with the Ping command. The PING
utility is the most commonly used message to verify connectivity to a remote device
within the network.

Front 191

You need to configure a default route on a Certkiller router. Which command will
configure a default route on a router?
A. CK1 (config)# ip route 0.0.0.0 10.1.1.0 10.1.1.1
B. CK1 (config)# ip default-route 10.1.1.0
C. CK1 (config)# ip default-gateway 10.1.1.0
D. CK1 (config)# ip route 0.0.0.0 0.0.0.0 10.1.1.1

Back 191

Answer: D

Hint 191

Explanation:
The command "IP route 0.0.0.0 0.0.0.0 <ip-address of the interface>" command is used
to configure a default route on a router. In this case, a default route with a next hop IP
address of 10.1.1.1 was configured.
Incorrect Answers:
A. This will be an invalid route, since the "10.1.1.0" value will specify the network mask,
which in this case is invalid.
B, C. These commands are invalid. The command "ip default-network" could be used,
but not "ip default-route" or "ip default-gateway". IP default-gateway is used on
switches, not routers.

Front 192

Static routing needs to be configured on router CK1 . In which situation would the
use of a static route be appropriate?
A. To configure a route to the first Layer 3 device on the network segment.
B. To configure a route from an ISP router into a corporate network.
C. To configure a route when the administrative distance of the current routing protocol
is too low.
D. To reach a network is more than 15 hops away.
E. To provide access to the Internet for enterprise hosts.
F. None of the above

Back 192

Answer: B

Hint 192

Explanation:
Static routes are special routes that the network administrator manually enters into the
router configuration. Stub networks are the ideal candidate for static routes.
There is no need to run a routing protocol over the WAN links between an ISP Router
and a corporate network when only a single Internet link exists.

Front 193

Which of the commands below can you use to configure a default route on router
CK1 ? (Select two answer choices)
A. CK1 (config)# ip route 0.0.0.0 0.0.0.0 E0
B. CK1 (config)# ip route 0.0.0.0 255.255.255.255 S0
C. CK1 (config-interface)# ip route 255.255.255.255 0.0.0.0 192.168.1.21
D. CK1 (config)# ip route 0.0.0.0 0.0.0.0 192.168.1.21
E. CK1 (config)# ip route 0.0.0.0 192.168.1.21 255.255.255.255
F. CK1 # ip default-network 0.0.0.0 192.168.1.21 255.255.255.255

Back 193

Answer: A, D

Hint 193

Explanation:
There are two ways to specify a default static route. One is to specify the interface to use
for forwarding packets, like the example in A. The other way is to specify the IP address
of the next hop router, such as the example in D. The ip route 0.0.0.0 0.0.0.0 command
uses the fact that network 0.0.0.0 is used by Cisco IOS software to represent the default
network.
Reference: CCNA ICND Exam Certification Guide By Wendell Odem Pg.524
Incorrect Answers:
B. All zero's must used for the subnet mask of a default route, not all 1's.
C. The default route is made in global configuration mode.
D, E. A subnet mask is not needed after the next hop router is specified

Front 194

Which of the following commands would you use to configure a default route to any
destination NOT found in the routing table of router CK1 ?
A. CK1 (config)# ip default-route 0.0.0.0 255.255.255.255 s0
B. CK1 (config)# ip route 0.0.0.0 255.255.255.255 s0
C. CK1 (config)# ip default-route 0.0.0.0 0.0.0.0 s0
D. CK1 (config)# ip route 0.0.0.0 0.0.0.0 s0
E. CK1 (config)# ip route any any e0
F. None of the above

Back 194

Answer: D

Hint 194

Explanation:
Choice D is the correct syntax for configuring a gateway of last resort. Note that an
alternative way is to specify the IP address of the next hop router, for example, "ip route
0.0.0.0 0.0.0.0 10.1.1.1."

Front 195

Some of the Certkiller routers have been configured with default routes. What are
some of the advantages of using default routes? (Choose two)
A. They establish routes that will never go down.
B. The keep routing tables small.
C. They require a great deal of CPU power.
D. The allow connectivity to remote networks that are not in the routing table.
E. They direct traffic from the Internet into corporate networks.

Back 195

Answer: B, D

Hint 195

Explanation:
Routers use default routing as a last resort when all other methods (directly connected,
static, or dynamic) have been exhausted. For stub networks, a single default static route
could be used to provide connectivity to the entire network. This is desirable for stub
networks where only a single link connects the remote location to the rest of the
networks. Because all of the traffic only has one link to use, a single default route will
make the routing table as small as possible, while providing for connectivity to networks
not in the routing table, since as traffic destined for the Internet.
Incorrect Answers:
A. Although default routes are normally statically assigned, these routes can still go
down. If the interface used as the default route should go down, or the next hop IP
address of the default route become unreachable, the static default route will go down.
C. Using static routes, including default routes, is the least CPU-intensive method of
routing.
E. To influence the way incoming traffic from the Internet gets to a corporation, BGP
routing would be used, not default routing.

Front 196

You have just configured a static default route on router CK1 . What is the purpose
of a default route?
A. It is a route to be used when the routing protocol fails.
B. It is a route configured by an ISP that sends traffic into a corporate network.
C. It is a route used when a packet is destined for a remote network that is not listed in
the routing table.
D. It is a route manually configured for a specific remote network for which a routing
protocol is not configured.
E. It is used to send traffic to a stub network.
F. None of the above

Back 196

Answer: C

Hint 196

Explanation:
Every IP host needs to have a default route either manually configured or dynamically
learned. Default routes provide end hosts a way out of their local subnet and routers with
a router of last resort if no other route (specifically relating to the destination) exists in
the routers route table.
Routers use default routing as a last resort when all other methods (directly connected,
static, or dynamic) have been exhausted. Routers inspect received datagrams to identify
the logical Network layer address of the ultimate destination. If a directly connected
static or dynamic route exists within the router's route table, it forwards the datagram.
If the destination remains unknown, that is, no method of routing has resulted in a
learned route; it forces the router to use a default route. Typically, administrators
implement default routes on point-to-point (a link with only two routers) or dial-up
connections, linking Certkiller .com's network to the outside work.
Reference: http://www.informit.com/articles/article.asp?p=26129&seqNum=4&rl=1

Front 197

On router CK1 the following configuration command was entered:
ip route 0.0.0.0 0.0.0.0 192.168.1.2
What is the result of adding this command to this router when it is already
configured for dynamic routing?
A. It configures the router to block routing updates from being sent to IP address
192.168.1.2.
B. It configures the router to send all packets to IP address 192.168.1.2 if the packets
match no other entry in the routing table.
C. It configures the router to drop all packets for which the destination network is
unknown.
D. It configures the router to send all packets to IP address 192.168.1.2.
E. It configures the router as a firewall, blocking all packets from IP address 192.168.1.2.
F. None of the above

Back 197

Answer: B

Hint 197

Explanation:
There is a special kind of static route called a default route, which is what this example is
showing. Sometimes a default route is called a "zero / zero" route. This is because the
network and subnet you are specifying, as the destination for the traffic it would match,
are all zeros. A default route says "for any traffic that does not match a specific route in
the routing table, send that traffic to this destination". In other words, a default route is a
"catch-all".

Front 198

If NVRAM in a Certkiller router lacks boot system commands, where does this
router look for the Cisco IOS by default?
A. ROM
B. RAM
C. Flash
D. Bootstrap
E. Startup-.config
F. None of the above

Back 198

Answer: C

Hint 198

Explanation:
Flash memory - Either an EEPROM or a PCMCIA card, Flash memory stores fully
functional IOS images and is the default location where the router gets its IOS at boot
time. Flash memory also can be used to store any other files, including configuration
files.
Reference:
CCNA Self-Study CCNA INTRO exam certification Guide (Cisco Press, ISBN
1-58720-094-5) page 187

Front 199

When you power up a Certkiller router; in what memory is the start-up
configuration normally stored in?
A. RAM
B. ROM
C. FLASH
D. NVRAM
E. None of the above

Back 199

Answer: D

Hint 199

Explanation:
The startup configuration is stored in the Non-Volatile RAM.
Incorrect Answers:
A, B: No configuration information is stored in RAM or ROM.
C. The IOS is normally stored in the flash memory, not the saved configuration.

Front 200

You are the administrator of the Certkiller network and you have forgotten the
password to one of your routers. After completing the password recovery procedure
the router returned to its normal operation. The config-register was set back to the
initial default value. What is this value?
A. 0x2112
B. 0x2104
C. 0x2102
D. 0x2142
E. 0x2100

Back 200

Answer: C

Front 201

You need to configure a default route on a Certkiller router. Which command will
configure a default route on a router?
A. CK1 (config)# ip route 0.0.0.0 10.1.1.0 10.1.1.1
B. CK1 (config)# ip default-route 10.1.1.0
C. CK1 (config)# ip default-gateway 10.1.1.0
D. CK1 (config)# ip route 0.0.0.0 0.0.0.0 10.1.1.1

Back 201

Answer: D

Hint 201

Explanation:
The command "IP route 0.0.0.0 0.0.0.0 <ip-address of the interface>" command is used
to configure a default route on a router. In this case, a default route with a next hop IP
address of 10.1.1.1 was configured.
Incorrect Answers:
A. This will be an invalid route, since the "10.1.1.0" value will specify the network mask,
which in this case is invalid.
B, C. These commands are invalid. The command "ip default-network" could be used,
but not "ip default-route" or "ip default-gateway". IP default-gateway is used on
switches, not routers.

Front 202

Static routing needs to be configured on router CK1 . In which situation would the
use of a static route be appropriate?
A. To configure a route to the first Layer 3 device on the network segment.
B. To configure a route from an ISP router into a corporate network.
C. To configure a route when the administrative distance of the current routing protocol
is too low.
D. To reach a network is more than 15 hops away.
E. To provide access to the Internet for enterprise hosts.
F. None of the above

Back 202

Answer: B

Hint 202

Explanation:
Static routes are special routes that the network administrator manually enters into the
router configuration. Stub networks are the ideal candidate for static routes.
There is no need to run a routing protocol over the WAN links between an ISP Router
and a corporate network when only a single Internet link exists.

Front 203

Which of the commands below can you use to configure a default route on router
CK1 ? (Select two answer choices)
A. CK1 (config)# ip route 0.0.0.0 0.0.0.0 E0
B. CK1 (config)# ip route 0.0.0.0 255.255.255.255 S0
C. CK1 (config-interface)# ip route 255.255.255.255 0.0.0.0 192.168.1.21
D. CK1 (config)# ip route 0.0.0.0 0.0.0.0 192.168.1.21
E. CK1 (config)# ip route 0.0.0.0 192.168.1.21 255.255.255.255
F. CK1 # ip default-network 0.0.0.0 192.168.1.21 255.255.255.255

Back 203

Answer: A, D

Hint 203

Explanation:
There are two ways to specify a default static route. One is to specify the interface to use
for forwarding packets, like the example in A. The other way is to specify the IP address
of the next hop router, such as the example in D. The ip route 0.0.0.0 0.0.0.0 command
uses the fact that network 0.0.0.0 is used by Cisco IOS software to represent the default
network.
Reference: CCNA ICND Exam Certification Guide By Wendell Odem Pg.524
Incorrect Answers:
B. All zero's must used for the subnet mask of a default route, not all 1's.
C. The default route is made in global configuration mode.
D, E. A subnet mask is not needed after the next hop router is specified

Front 204

Which of the following commands would you use to configure a default route to any
destination NOT found in the routing table of router CK1 ?
A. CK1 (config)# ip default-route 0.0.0.0 255.255.255.255 s0
B. CK1 (config)# ip route 0.0.0.0 255.255.255.255 s0
C. CK1 (config)# ip default-route 0.0.0.0 0.0.0.0 s0
D. CK1 (config)# ip route 0.0.0.0 0.0.0.0 s0
E. CK1 (config)# ip route any any e0
F. None of the above

Back 204

Answer: D

Hint 204

Explanation:
Choice D is the correct syntax for configuring a gateway of last resort. Note that an
alternative way is to specify the IP address of the next hop router, for example, "ip route
0.0.0.0 0.0.0.0 10.1.1.1."

Front 205

Some of the Certkiller routers have been configured with default routes. What are
some of the advantages of using default routes? (Choose two)
A. They establish routes that will never go down.
B. The keep routing tables small.
C. They require a great deal of CPU power.
D. The allow connectivity to remote networks that are not in the routing table.
E. They direct traffic from the Internet into corporate networks.

Back 205

Answer: B, D

Hint 205

Explanation:
Routers use default routing as a last resort when all other methods (directly connected,
static, or dynamic) have been exhausted. For stub networks, a single default static route
could be used to provide connectivity to the entire network. This is desirable for stub
networks where only a single link connects the remote location to the rest of the
networks. Because all of the traffic only has one link to use, a single default route will
make the routing table as small as possible, while providing for connectivity to networks
not in the routing table, since as traffic destined for the Internet.
Incorrect Answers:
A. Although default routes are normally statically assigned, these routes can still go
down. If the interface used as the default route should go down, or the next hop IP
address of the default route become unreachable, the static default route will go down.
C. Using static routes, including default routes, is the least CPU-intensive method of
routing.
E. To influence the way incoming traffic from the Internet gets to a corporation, BGP
routing would be used, not default routing.

Front 206

You have just configured a static default route on router CK1 . What is the purpose
of a default route?
A. It is a route to be used when the routing protocol fails.
B. It is a route configured by an ISP that sends traffic into a corporate network.
C. It is a route used when a packet is destined for a remote network that is not listed in
the routing table.
D. It is a route manually configured for a specific remote network for which a routing
protocol is not configured.
E. It is used to send traffic to a stub network.
F. None of the above

Back 206

Answer: C

Hint 206

Explanation:
Every IP host needs to have a default route either manually configured or dynamically
learned. Default routes provide end hosts a way out of their local subnet and routers with
a router of last resort if no other route (specifically relating to the destination) exists in
the routers route table.
Routers use default routing as a last resort when all other methods (directly connected,
static, or dynamic) have been exhausted. Routers inspect received datagrams to identify
the logical Network layer address of the ultimate destination. If a directly connected
static or dynamic route exists within the router's route table, it forwards the datagram.
If the destination remains unknown, that is, no method of routing has resulted in a
learned route; it forces the router to use a default route. Typically, administrators
implement default routes on point-to-point (a link with only two routers) or dial-up
connections, linking Certkiller .com's network to the outside work.
Reference: http://www.informit.com/articles/article.asp?p=26129&seqNum=4&rl=1

Front 207

On router CK1 the following configuration command was entered:
ip route 0.0.0.0 0.0.0.0 192.168.1.2
What is the result of adding this command to this router when it is already
configured for dynamic routing?
A. It configures the router to block routing updates from being sent to IP address
192.168.1.2.
B. It configures the router to send all packets to IP address 192.168.1.2 if the packets
match no other entry in the routing table.
C. It configures the router to drop all packets for which the destination network is
unknown.
D. It configures the router to send all packets to IP address 192.168.1.2.
E. It configures the router as a firewall, blocking all packets from IP address 192.168.1.2.
F. None of the above

Back 207

Answer: B

Hint 207

Explanation:
There is a special kind of static route called a default route, which is what this example is
showing. Sometimes a default route is called a "zero / zero" route. This is because the
network and subnet you are specifying, as the destination for the traffic it would match,
are all zeros. A default route says "for any traffic that does not match a specific route in
the routing table, send that traffic to this destination". In other words, a default route is a
"catch-all".

Front 208

If NVRAM in a Certkiller router lacks boot system commands, where does this
router look for the Cisco IOS by default?
A. ROM
B. RAM
C. Flash
D. Bootstrap
E. Startup-.config
F. None of the above

Back 208

Answer: C

Hint 208

Explanation:
Flash memory - Either an EEPROM or a PCMCIA card, Flash memory stores fully
functional IOS images and is the default location where the router gets its IOS at boot
time. Flash memory also can be used to store any other files, including configuration
files.
Reference:
CCNA Self-Study CCNA INTRO exam certification Guide (Cisco Press, ISBN
1-58720-094-5) page 187

Front 209

When you power up a Certkiller router; in what memory is the start-up
configuration normally stored in?
A. RAM
B. ROM
C. FLASH
D. NVRAM
E. None of the above

Back 209

Answer: D

Hint 209

Explanation:
The startup configuration is stored in the Non-Volatile RAM.
Incorrect Answers:
A, B: No configuration information is stored in RAM or ROM.
C. The IOS is normally stored in the flash memory, not the saved configuration.

Front 210

You are the administrator of the Certkiller network and you have forgotten the
password to one of your routers. After completing the password recovery procedure
the router returned to its normal operation. The config-register was set back to the
initial default value. What is this value?
A. 0x2112
B. 0x2104
C. 0x2102
D. 0x2142
E. 0x2100

Back 210

Answer: C

Front 211

You need to configure a default route on a Certkiller router. Which command will
configure a default route on a router?
A. CK1 (config)# ip route 0.0.0.0 10.1.1.0 10.1.1.1
B. CK1 (config)# ip default-route 10.1.1.0
C. CK1 (config)# ip default-gateway 10.1.1.0
D. CK1 (config)# ip route 0.0.0.0 0.0.0.0 10.1.1.1

Back 211

Answer: D

Hint 211

Explanation:
The command "IP route 0.0.0.0 0.0.0.0 <ip-address of the interface>" command is used
to configure a default route on a router. In this case, a default route with a next hop IP
address of 10.1.1.1 was configured.
Incorrect Answers:
A. This will be an invalid route, since the "10.1.1.0" value will specify the network mask,
which in this case is invalid.
B, C. These commands are invalid. The command "ip default-network" could be used,
but not "ip default-route" or "ip default-gateway". IP default-gateway is used on
switches, not routers.

Front 212

Static routing needs to be configured on router CK1 . In which situation would the
use of a static route be appropriate?
A. To configure a route to the first Layer 3 device on the network segment.
B. To configure a route from an ISP router into a corporate network.
C. To configure a route when the administrative distance of the current routing protocol
is too low.
D. To reach a network is more than 15 hops away.
E. To provide access to the Internet for enterprise hosts.
F. None of the above

Back 212

Answer: B

Hint 212

Explanation:
Static routes are special routes that the network administrator manually enters into the
router configuration. Stub networks are the ideal candidate for static routes.
There is no need to run a routing protocol over the WAN links between an ISP Router
and a corporate network when only a single Internet link exists.

Front 213

Which of the commands below can you use to configure a default route on router
CK1 ? (Select two answer choices)
A. CK1 (config)# ip route 0.0.0.0 0.0.0.0 E0
B. CK1 (config)# ip route 0.0.0.0 255.255.255.255 S0
C. CK1 (config-interface)# ip route 255.255.255.255 0.0.0.0 192.168.1.21
D. CK1 (config)# ip route 0.0.0.0 0.0.0.0 192.168.1.21
E. CK1 (config)# ip route 0.0.0.0 192.168.1.21 255.255.255.255
F. CK1 # ip default-network 0.0.0.0 192.168.1.21 255.255.255.255

Back 213

Answer: A, D

Hint 213

Explanation:
There are two ways to specify a default static route. One is to specify the interface to use
for forwarding packets, like the example in A. The other way is to specify the IP address
of the next hop router, such as the example in D. The ip route 0.0.0.0 0.0.0.0 command
uses the fact that network 0.0.0.0 is used by Cisco IOS software to represent the default
network.
Reference: CCNA ICND Exam Certification Guide By Wendell Odem Pg.524
Incorrect Answers:
B. All zero's must used for the subnet mask of a default route, not all 1's.
C. The default route is made in global configuration mode.
D, E. A subnet mask is not needed after the next hop router is specified

Front 214

Which of the following commands would you use to configure a default route to any
destination NOT found in the routing table of router CK1 ?
A. CK1 (config)# ip default-route 0.0.0.0 255.255.255.255 s0
B. CK1 (config)# ip route 0.0.0.0 255.255.255.255 s0
C. CK1 (config)# ip default-route 0.0.0.0 0.0.0.0 s0
D. CK1 (config)# ip route 0.0.0.0 0.0.0.0 s0
E. CK1 (config)# ip route any any e0
F. None of the above

Back 214

Answer: D

Hint 214

Explanation:
Choice D is the correct syntax for configuring a gateway of last resort. Note that an
alternative way is to specify the IP address of the next hop router, for example, "ip route
0.0.0.0 0.0.0.0 10.1.1.1."

Front 215

Some of the Certkiller routers have been configured with default routes. What are
some of the advantages of using default routes? (Choose two)
A. They establish routes that will never go down.
B. The keep routing tables small.
C. They require a great deal of CPU power.
D. The allow connectivity to remote networks that are not in the routing table.
E. They direct traffic from the Internet into corporate networks.

Back 215

Answer: B, D

Hint 215

Explanation:
Routers use default routing as a last resort when all other methods (directly connected,
static, or dynamic) have been exhausted. For stub networks, a single default static route
could be used to provide connectivity to the entire network. This is desirable for stub
networks where only a single link connects the remote location to the rest of the
networks. Because all of the traffic only has one link to use, a single default route will
make the routing table as small as possible, while providing for connectivity to networks
not in the routing table, since as traffic destined for the Internet.
Incorrect Answers:
A. Although default routes are normally statically assigned, these routes can still go
down. If the interface used as the default route should go down, or the next hop IP
address of the default route become unreachable, the static default route will go down.
C. Using static routes, including default routes, is the least CPU-intensive method of
routing.
E. To influence the way incoming traffic from the Internet gets to a corporation, BGP
routing would be used, not default routing.

Front 216

You have just configured a static default route on router CK1 . What is the purpose
of a default route?
A. It is a route to be used when the routing protocol fails.
B. It is a route configured by an ISP that sends traffic into a corporate network.
C. It is a route used when a packet is destined for a remote network that is not listed in
the routing table.
D. It is a route manually configured for a specific remote network for which a routing
protocol is not configured.
E. It is used to send traffic to a stub network.
F. None of the above

Back 216

Answer: C

Hint 216

Explanation:
Every IP host needs to have a default route either manually configured or dynamically
learned. Default routes provide end hosts a way out of their local subnet and routers with
a router of last resort if no other route (specifically relating to the destination) exists in
the routers route table.
Routers use default routing as a last resort when all other methods (directly connected,
static, or dynamic) have been exhausted. Routers inspect received datagrams to identify
the logical Network layer address of the ultimate destination. If a directly connected
static or dynamic route exists within the router's route table, it forwards the datagram.
If the destination remains unknown, that is, no method of routing has resulted in a
learned route; it forces the router to use a default route. Typically, administrators
implement default routes on point-to-point (a link with only two routers) or dial-up
connections, linking Certkiller .com's network to the outside work.
Reference: http://www.informit.com/articles/article.asp?p=26129&seqNum=4&rl=1

Front 217

On router CK1 the following configuration command was entered:
ip route 0.0.0.0 0.0.0.0 192.168.1.2
What is the result of adding this command to this router when it is already
configured for dynamic routing?
A. It configures the router to block routing updates from being sent to IP address
192.168.1.2.
B. It configures the router to send all packets to IP address 192.168.1.2 if the packets
match no other entry in the routing table.
C. It configures the router to drop all packets for which the destination network is
unknown.
D. It configures the router to send all packets to IP address 192.168.1.2.
E. It configures the router as a firewall, blocking all packets from IP address 192.168.1.2.
F. None of the above

Back 217

Answer: B

Hint 217

Explanation:
There is a special kind of static route called a default route, which is what this example is
showing. Sometimes a default route is called a "zero / zero" route. This is because the
network and subnet you are specifying, as the destination for the traffic it would match,
are all zeros. A default route says "for any traffic that does not match a specific route in
the routing table, send that traffic to this destination". In other words, a default route is a
"catch-all".

Front 218

If NVRAM in a Certkiller router lacks boot system commands, where does this
router look for the Cisco IOS by default?
A. ROM
B. RAM
C. Flash
D. Bootstrap
E. Startup-.config
F. None of the above

Back 218

Answer: C

Hint 218

Explanation:
Flash memory - Either an EEPROM or a PCMCIA card, Flash memory stores fully
functional IOS images and is the default location where the router gets its IOS at boot
time. Flash memory also can be used to store any other files, including configuration
files.
Reference:
CCNA Self-Study CCNA INTRO exam certification Guide (Cisco Press, ISBN
1-58720-094-5) page 187

Front 219

When you power up a Certkiller router; in what memory is the start-up
configuration normally stored in?
A. RAM
B. ROM
C. FLASH
D. NVRAM
E. None of the above

Back 219

Answer: D

Hint 219

Explanation:
The startup configuration is stored in the Non-Volatile RAM.
Incorrect Answers:
A, B: No configuration information is stored in RAM or ROM.
C. The IOS is normally stored in the flash memory, not the saved configuration.

Front 220

You are the administrator of the Certkiller network and you have forgotten the
password to one of your routers. After completing the password recovery procedure
the router returned to its normal operation. The config-register was set back to the
initial default value. What is this value?
A. 0x2112
B. 0x2104
C. 0x2102
D. 0x2142
E. 0x2100

Back 220

Answer: C

Front 221

Which is the correct fallback sequence for loading the Cisco IOS?
A. ROM, Flash, NVRAM
B. ROM, TFTP server, Flash
C. Flash, TFTP server, ROM
D. Flash, NVRAM, RAM

Back 221

Answer: C

Hint 221

Explanation:
By default, a Cisco IOS router will normally boot up from flash where the IOS is stored.
If the IOS in not found or has become corrupted, the router will then send an all hosts
broadcast (255.255.255.255) to find a TFTP server to download the IOS from. Should
that fail, the router will boot up in ROM Monitor mode as a last resort

Front 222

A Cisco router has been configured, and the copy running-config startup-config
command has been issued. When the router is power cycled, the router prompts
with:
"Would you like to enter the initial configuration dialog? [yes/no]"
Why has this occurred?
A. There is an error in the router DRAM.
B. Te IOS image is corrupt.
C. The configuration register is set to 0x2142.
D. The TFTP server that contains the router configuration file is unreachable.
E. A boot system configuration command has placed the router into setup mode

Back 222

Answer: C

Hint 222

When the configuration setting is set to 0x2142, the router will ignore the contents of the
NVRAM information. More specifically, this setting will:
1. Ignores break
2. Boots into ROM if initial boot fails
3. 9600 console baud rate
4. Ignores the contents of Non-Volatile RAM (NVRAM) (ignores configuration)

Front 223

What is the purpose of using the copy flash tftp command on a router?
A. To copy an IOS image to the router
B. To create a backup copy of the IOS
C. To move the IOS image from a server to the router
D. To backup the router configuration to a server

Back 223

Answer: B

Hint 223

Explanation:
When upgrading the IOS on a router, if there is enough space to copy the system image
file, then the original one can be retained and the new file can be copied in the additional
memory space. If there is not enough space available, as in this case, then the existing file
from the Flash is erased while downloading a new one. It is a good practice to backup the
existing system image to the TFTP server using the "copy flash tftp" command.
Reference: http://www.cisco.com/warp/public/63/copyimage.html

Front 224

Before installing a new, upgraded version of the IOS, what should be checked on the
router, and which command should be used to gather this information? (Choose
two)
A. show running-config
B. show version
C. the version of the bootstrap software present on the router
D. the amount of available ROM
E. the amount of available flash and RAM memory
F. show processes

Back 224

Answer: B, E

Hint 224

Explanation:
To upgrade the IOS, the first two steps are:
1. Download the Cisco IOS software image to your workstation or PC.
2. Install the new Cisco IOS software image in the outbound directory of the TFTP
server.
The TFTP server looks for the router's Cisco IOS software image in this directory. Make
sure that the image you want to copy to your Flash is in this directory.
Check the memory requirements needed for the Software image being upgraded, which is
mentioned in the Downloads download page. Using the show version command, verify
that you have enough memory.

Front 225

Which of the commands below would you enter if you wanted to see the
configuration register of your router?
A. show boot
B. show flash
C. show register
D. show version
E. show config
F. None of the above

Back 225

Answer: D

Hint 225

Explanation:
To display the configuration of the system hardware, the software version, the names and
sources of configuration files, and the boot images, use the show version command in
EXEC mode.
Example:
The following is sample output from the show version command:
Router1> show version
Cisco Internetwork Operating System Software
IOS (tm) 7200 Software (C7200-J-M), Experimental Version 11.3(19970915:164752) [
hampton-nitro-baseline 249]
Copyright (c) 1986-1997 by cisco Systems, Inc.
Compiled Wed 08-Oct-97 06:39 by hampton
Image text-base: 0x60008900, data-base: 0x60B98000
ROM: System Bootstrap, Version 11.1(11855) [beta 2], INTERIM SOFTWARE
BOOTFLASH: 7200 Software (C7200-BOOT-M), Version 11.1(472), RELEASE
Router1 uptime is 23 hours, 33 minutes
cisco 7206 (NPE150) processor with 57344K/8192K bytes of memory.
R4700 processor, Implementation 33, Revision 1.0 (512KB Level 2 Cache)
Last reset from power-on
Bridging software.
X.25 software, Version 3.0.0.
SuperLAT software copyright 1990 by Meridian Technology Corp).
TN3270 Emulation software.
8 Ethernet/IEEE 802.3 interface(s)
2 FastEthernet/IEEE 802.3 interface(s)
4 Token Ring/IEEE 802.5 interface(s)
4 Serial network interface(s)
1 FDDI network interface(s)
125K bytes of non-volatile configuration memory.
1024K bytes of packet SRAM memory.
20480K bytes of Flash PCMCIA card at slot 0 (Sector size 128K).
20480K bytes of Flash PCMCIA card at slot 1 (Sector size 128K).
4096K bytes of Flash internal SIMM (Sector size 256K).
Configuration register is 0x2102

Front 226

After logging into a router, you type in "enable" and then enter the correct
password when prompted. What is the current router prompt symbol at this point?
A. >
B. #
C. ?
D. *
E. All of the above
F. None of the above

Back 226

Answer: B

Hint 226

Explanation:
When you enter the privileged mode by typing enable the router prompt will change to a
# character.
Incorrect Answers
A. This is the prompt given after initially logging on.
C, D. These are not valid router prompts.

Front 227

In the Cisco IOS, what is the definition of a global command?
A. A command that can be entered in any configuration mode.
B. A command that supports all protocols.
C. A command that is implemented in all IOS versions.
D. A command that is set once and affects the entire router.
E. A command that is available in every release of IOS.

Back 227

Answer: D

Hint 227

Explanation:
When you enter global configuration mode and enter a command, it is applied to the
running configuration file that is currently running in ram. The configuration of a global
command affects the entire router. An example of a global command is one used for the
hostname of the router.
Incorrect Answers:
A. Global configuration commands must be performed while in global configuration
mode. For example, when you are in the interface configuration mode, you most likely
will need to exit out into global mode to type in the commands.
B. Global commands do not necessarily support every protocol.
C. This is not necessarily true, since there are certain global commands that are supported
on one feature set that are not on a different feature set of IOS.
E. Global commands can become outdated, and can be replaced by newer commands in
the newer releases of IOS.

Front 228

Which of the following commands will display the name of the IOS image file being
used in a Certkiller router?
A. Router# show IOS
B. Router# show version
C. Router# show image
D. Router# show protocols
E. Router# show flash

Back 228

Answer: B, E

Hint 228

Explanation:
Different Cisco IOS versions and feature sets will ultimately dictate the size of the IOS
file and the amount of Flash and DRAM memory required to run the IOS. If you are
planning to upgrade to a new IOS, you must make sure that you have enough memory
(the more, the better) in your device. To see the amount of Flash you have and the current
IOS file stored in Flash memory, utilize the show flash command as follows:
Router>show flashSystem flash directory:File Length Name/status 1 5510192
c2600-is-mz.120-3.T3.bin[5510256 bytes used, 2878352 available, 8388608 total]8192K
bytes of processor board System flash (Read/Write)Typically, the filename of the IOS
file in Flash correctly reflects the actual IOS version running currently on the device.
However, an administrator can easily change the filename to his or her own purposes, or
there could be multiple IOS files stored on the Flash and you are not sure which one is
running currently. To ensure the correct version of IOS, use the widely practical show
version command.
Incorrect Answers:
A, C. These are invalid commands.
D. The command "show protocols" will show the routed protocols in use by the router
and by interface conditions and their IP address, if configured

Front 229

After making changes to the router, you issue the "copy running-config
startup-config" command to save changes. After reloading the router, the router
comes up in setup mode. You again make changes, save them, and reboot. Again,
the router comes up in setup mode.
What is the most likely cause of this?
A. The NVRAM is corrupted.
B. The boot system commands were omitted in the configuration.
C. The configuration register setting is incorrect.
D. The upgraded configuration incompatible with the hardware platform.
E. The upgraded IOS incompatible with the hardware.
F. None of the above

Back 229

Answer: C

Hint 229

Explanation:
When you enter the command, "copy running-config startup-config" you save your
current settings to NVRAM. The problem described in this question is that it appears the
router is set to bypass the NVRAM, making it come up in the initial configuration dialog.
The most likely cause of a router with the configuration register settings set incorrectly is
that the router recently went through the password recovery procedure.

Front 230

You need to upgrade the IOS of an existing router on your network. The new IOS
image is located on a TFTP server that you have set up within the network. What
command should you issue in order to download the new IOS version?
A. Router# copy tftp flash
B. Router# copy flash run
C. Router(config)# restore flash
D. Router(config)# repair flash
E. Router# copy flash tftp
F. Router# copy start flash
G. None of the above

Back 230

Answer: A

Hint 230

Explanation:
The command "copy tftp flash" will copy the new IOS version upgrade from your
networks TFTP server (assuming of course you have a TFTP server with the new version
of IOS standing by).
Incorrect Answers:
C, D. The copy tftp flash command should be issued from the enable command prompt. It
is not necessary to go into configuration mode.
E. This will have the reverse effect, and will copy the IOS image on your router onto a
folder in your TFTP server

Front 231

What kind of information can you deduce from an IOS image file name? (Select
three answer choices)
A. Distribution channel failures
B. Feature capabilities
C. Memory capacity needs
D. Hardware product platform
E. Programming language requirements
F. Run location and compression status

Back 231

Answer: B, D, F

Hint 231

Explanation:
Image Naming Conventions:
You can identify the platform, features, and image location by the name of
the image. The naming convention is platform-features-type for images that
are stored on a UNIX system.
The platform variable indicates which platforms can use this image. Examples
of platform variables include rsp (Cisco 7000 series with RSP7000 and Cisco
7500 series), c1600 (Cisco 1600 series), and c1005 (Cisco 1005).
The features variable identifies the feature sets supported by the image.
The type field can contain the following characters:
f-The image runs from Flash memory.
m-The image runs from RAM.
r-The image runs from ROM.
l-The image is relocatable.
z-The image is zip compressed.
x-The image is mzip compressed

Front 232

You wish to upgrade the IOS of a router without removing the image currently
installed.
What command will display the amount of memory that is being used by the
current IOS image and whether there is enough room available to hold both the
current and new images?
A. Router# show version
B. Router# show flash
C. Router# show memory
D. Router# show buffers
E. Router# show running-config
F. All of the above

Back 232

Answer: B

Hint 232

Explanation:
The "show flash" command is used to display the layout and contents of the flash
memory file system. It will show name of the file system, as well as the number of bytes
used and the number available within the flash memory.

Front 233

You are a trainee technician at Certkiller , Inc. Your instructor tells you to backup
an IOS image of a Cisco device to a Windows 2003 server on the network.
What should you do first? (Choose three)
A. Make sure that the network server can be accessed.
B. Check that the authentication for access is set.
C. Assure that the network server has adequate space for the code image.
D. Verify any file naming and path requirements.
E. Make sure that the server can load and run the bootstrap code.

Back 233

Answer: A, C, D

Hint 233

Explanation:
In order to properly back up the Cisco IOS image onto a Windows server, you should
ensure that the server is reachable and that you have the proper permissions to save files
to the server. In addition to this, the server will need enough space to hold the backup
file.
Incorrect Answers:
E. In order to simply back up the IOS file, the server needs to only be able to save it to a
hard disk. It does not need to load, read, or boot the image.

Front 234

Router CK1 is not operating as expected and you want to verify that the router
booted using the correct IOS image. Which command should be used to determine
which IOS is running on the router?
A. show memory
B. show flash
C. show version
D. show startup-config
E. show config-register
F. None of the above

Back 234

Answer: C

Hint 234

Explanation:
The "show version" command displays info about the router and IOS running in RAM as

Front 235

You wish to increase the security of all of the routers within the Certkiller network.
What can be done to secure the virtual terminal interfaces on a router? (Choose
two)
A. Administratively shut down the interface.
B. Physically secure the interface.
C. Create an access list and apply it to the virtual terminal interfaces with the
access-group command.
D. Configure a virtual terminal password and login process.
E. Enter an access list and apply it to the virtual terminal interfaces using the access-class
command

Back 235

Answer: D, E

Hint 235

Explanation:
There are a total of 5 logical Virtual terminal interfaces in a Cisco router (lines 0-4) and
they are used for remote access into the device via telnet. Configuring these interfaces
correctly with a login and password information can be used for security, as each user
will be prompted for a password in order to obtain access. A second method is to use the
"access-class" command. Combined with an access list, this command can be used to
specify the hosts or networks that will be allow access to the device.
Incorrect Answers:
A. Virtual terminal interfaces are logical interfaces that can not be manually shut down.
B. Virtual terminal lines are logical interfaces that reside within a router, so there is
nothing that can be physically secured.
C. This command is used with access-lists for LAN and WAN interfaces, but is not used
for the VTY lines.

Front 236

On router CK1 , the Certkiller network administrator issued the "service
password-encryption" command. What is the effect of this configuration command?
A. Only passwords configured after the command has been entered will be encrypted.
B. Only the enable password will be encrypted.
C. It will encrypt all current and future passwords.
D. Only the enable secret password will be encrypted.
E. It will encrypt the secret password and remove the enable secret password from the
configuration.
F. None of the above

Back 236

Answer: C

Front 237

You want the text "Unauthorized access pr ohibited!" to be displayed before the
login prompt every time someone tries to initiate a Telnet session to a Certkiller
router, as shown in the example below:
Router#telnet 192.168.15.1
Trying 192.168.15.1 ... Open
Unauthorized access prohibited!
User Access Verification
Password:
Which command can be used to configure this message?
A. login banner x Unauthorized access prohibited! X
B. banner exec y Unauthorized access prohibited! Y
C. banner motd x Unauthorized access prohibited! X
D. vty motd "Unauthorized access prohibited!"
E. None of the above

Back 237

Answer: C

Hint 237

Explanation:
The message text that is displayed when users log into the router is called the "message
of the day" banner, and is it can be changed with the "banner motd" command as shown
in answer choice C.

Front 238

What IOS command verifies connectivity between two hosts on the Certkiller
network by sending and receiving ICMP echo messages?
A. ping
B. tracert
C. netstat
D. show cdp neighbors detail
E. show ip route
F. traceroute
G. ipconfig

Back 238

Answer: A

Hint 238

Explanation:
Packet Internet Groper (PING) uses ICMP echo requests and replies to verify network
connectivity. It is most commonly used to verify connectivity to another device and to
monitor the operational status of a device

Front 239

What kind of message does a PING send out to test connectivity?
A. ICMP echo request
B. Information interrupt request
C. Timestamp reply
D. Source quench
E. None of the above

Back 239

Answer: A

Hint 239

Explanation:
The ping command sends an ICMP echo request packet to the stated destination address.
The TCP/IP software at the destination then replies to the ping echo request packet with a
similar packet, called the ICMP echo reply.
Reference: CCNA Self-Study CCNA ICND exam certification Guide (Cisco Press,
ISBN 1-58720-083-X) Page 146

Front 240

Why was the "show processes" command used on a Certkiller router before a debug
command was entered on it?
A. To verify that the CPU utilization is low enough to handle the effects of a debug
command
B. To verify the amount of space in flash memory
C. To view the number of timers that are currently in use
D. To check if the load meter file has enough space left to store the output of the debug
command
E. To verify the IOS version that is running
F. None of the above

Back 240

Answer: A

Hint 240

Explanation:
The show processes command displays information about the active processes. Issue the
show processes cpu command to display detailed CPU utilization statistics on these
processes and the show processes memory command to show the amount of memory
used.
The following is a sample output of the show processes command:
CK1 #show processes
CPU utilization for five seconds: 0%/0%; one minute: 0%; five
minutes: 0%
PID Q Ty PC Runtime(ms) Invoked uSecs Stacks TTY Process
1 C sp 602F3AF0 0 1627 0 2600/3000 0 Load Meter
2 L we 60C5BE00 4 136 29 5572/6000 0 CEF Scanner
3 L st 602D90F8 1676 837 2002 5740/6000 0 Check heaps
4 C we 602D08F8 0 1 0 5568/6000 0 Chunk Manager
5 C we 602DF0E8 0 1 0 5592/6000 0 Pool Manager
6 M st 60251E38 0 2 0 5560/6000 0 Timers
7 M we 600D4940 0 2 0 5568/6000 0 Serial Backgroun
8 M we 6034B718 0 1 0 2584/3000 0 OIR Handler
9 M we 603FA3C8 0 1 0 5612/6000 0 IPC Zone Manager
It is always a good idea to check the CPU utilization levels before doing anything that
may increase the CPU load, such as using debug commands.

Front 241

A new Certkiller is using an IEEE 802.11b a wireless LAN. What is the maximum
data rate specified for this WLAN?
A. 11 mbps
B. 100 mbps
C. 54 mbps
D. 10 mbps
E. 1000 mbps
F. 16 mbps
G. None of the above

Back 241

Answer: A

Hint 241

Explanation:
The maximum speed for 802.11b is 11 Mbps.
Incorrect Answers:
A. This is the maximum speed for legacy Ethernet networks.
C. This is the maximum speed supported by the other prevalent wireless standards,
802.11a and 802.11g.
D, E. This is the maximum speed of Ethernet and Gig E connections.
F. This is the maximum data rate for token ring.

Front 242

Which IEEE standard is used to define Wi-Fi?
A. IEEE 802.3
B. IEEE 802.5
C. IEEE 802.11h
D. IEEE 802.11c
E. IEEE 802.11

Back 242

Answer: E

Hint 242

Explanation:
IEEE 802.11 was the original standard for wireless networks. However, the standard had
a few ambiguities allowed for potential problems with compatibility between devices. To
ensure compatibility, a group of companies formed the Wireless Ethernet Compatibility
Alliance (WECA), which has come to be known as the Wi-Fi Alliance, to ensure that
their products would work together. The term Wi-Fi is now used to refer to any IEEE
802.11 wireless network products that have passed the Wi-Fi Alliance certification tests.
Incorrect Answers:
A. This is the standard used for Ethernet networks.
B. This is the standard used in Token Ring networks.
C, D: These standards are not currently used. The most prevalent types of wireless
802.11 networks are 802.11a, 802.11b, and 802.11g.

Front 243

802.1b is being utilized in the Certkiller wireless network. Which spread spectrum
technology does the 802.1b standard define for operation in this network?
A. FHSS
B. IR
C. DSSS and FHSS
D. DSSS
E. IR, FHSS and DSSS
F. None of the above

Back 243

Answer: D

Hint 243

Explanation:
In telecommunications, direct-sequence spread spectrum (DSSS) is a modulation
technique. As with other spread spectrum technologies, the transmitted signal takes up
more bandwidth than the information signal that is being modulated. The name 'spread
spectrum' comes from the fact that the carrier signals occur over the full bandwidth
(spectrum) of a device's transmitting frequency.

Front 244

Two Certkiller workers have established wireless communication directly between
their wireless laptops. What type of wireless topology has been created by these
Certkiller employees?
A. ESS
B. IBSS
C. SSID
D. BSS
E. None of the above

Back 244

Answer: B

Hint 244

Explanation:
An independent BSS (IBSS) is an ad-hoc network that contains no access points, which
means they can not connect to any other basic service set

Front 245

Three access points have been installed and configured to cover a small remote
Certkiller office. What term defines the wireless topology?
A. SSID
B. BSS
C. ESS
D. IBSS
E. ASS
F. None of the above

Back 245

Answer: C

Hint 245

A single wireless AP supporting one or multiple wireless clients is known as a Basic
Service Set (BSS). A set of two or more wireless APs connected to the same wired
network is known as an Extended Service Set (ESS). An ESS is a single logical network
segment (also known as a subnet), and is identified by its SSID

Front 246

A single 802.11g access point has been configured and installed in the center of a
square shaped Certkiller office. A few wireless Certkiller users are experiencing slow
performance and drops while most users are operating at peak efficiency. From the
list below, what are three likely causes of this problem? (Choose three)
A. Null SSID
B. Mismatched TKIP encryption
C. Cordless phones
D. Antenna type or direction
E. Mismatched SSID
F. Metal file cabinets
G. Microwave ovens in the break room

Back 246

Answer: C, D, F

Hint 246

Explanation:
C: If you have cordless phones or other wireless electronics in your home or office, your
computer might not be able to "hear" your router over the noise from the other wireless
devices. To quiet the noise, avoid wireless electronics that use the 2.8GHz frequency.
Instead, look for cordless phones that use the 5.8GHz or 900MHz frequencies.
D: The antennas supplied with your router are designed to be omni-directional, meaning
they broadcast in all directions around the router. If your router is near an outside wall,
half of the wireless signals will be sent outside your office, and much of your router's
power will be wasted.
Since most users operate at peak efficiency in our example, it could be that a few of the
users are simply placed too far from the antenna, or the antenna is not placed in the center
of the office.
F: Metal, walls, and floors will interfere with your router's wireless signals. The closer
your router is to these obstructions, the more severe the interference, and the weaker your
connection will be.

Front 247

In an effort to increase security within the Certkiller wireless network, WPA is being
utilized. Which two statements shown below best describe the wireless security
standard that is defined by WPA? (Choose two)
A. It requires use of an open authentication method
B. It specifies use of a static encryption key that must be changed frequently to enhance
security
C. It includes authentication by PSK
D. It specifies the use of dynamic encryption keys that change each time a client
establishes a connection
E. It requires that all access points and wireless devices use the same encryption key
F. WPA works only with Cisco access points

Back 247

Answer: C, D

Front 248

Certkiller has chosen WPA over WEP in their wireless network. What is one reason
why WPA encryption is preferred over WEP in this network?
A. The WPA key values remain the same until the client configuration is changed.
B. The values of WPA keys can change dynamically while the system is used.
C. The access point and the client are manually configured with different WPA key
values.
D. A WPA key is longer and requires more special characters than the WEP key.
E. None of the above

Back 248

Answer: B

Front 249

You need to determine the proper security settings on a new Certkiller
WLAN-capable office. Which encryption type would WPA2 use in this office?
A. PSK
B. AES-CCMP
C. PPK via IV
D. TKIP/MIC
E. None of the above

Back 249

Answer: B

Hint 249

Explanation:
In 2004, the IEEE 802.11i task group responsible for Wi-Fi security for the WLAN
provided a series of recommendations to fix known problems with Wireless Equivalent
Privacy (WEP). Its recommendations included using encryption techniques known as
Advanced Encryption Standard Counter-Mode Cipher Block Chaining (AES-CCMP) or
AES for short.
AES is not the end of the story, as the industry had a problem when it moved from WEP
to AES. What could be done, for example, about legacy devices that could not support
the upgrade to AES? The IEEE 802.11i task group recommended using the Temporal
Key Integrity Protocol (TKIP). As a patch, TKIP is not as secure as AES, but it protects
against all currently known attacks.
The urgent need to fix WEP caused the Wi-Fi Alliance to develop security patch
recommendations for Wi-Fi Protected Access (WPA) before the IEEE finalized
standards. WPA was drawn from an early draft of the IEEE 802.11i standard, and there
are significant differences between WPA and TKIP. What is similar is that neither the
WPA patch for WEP nor the TKIP patch is as secure as AES.
The Wi-Fi Alliance later came out with a new security recommendation-WPA, version 2
(WPA2)-to make WPA consistent with IEEE 802.11i standards. One improvement to
WPA2 was the recommendation to use AES-CCMP encryption mode. WPA2 has thus
become synonymous with AES.
The table below summarizes the different encryption algorithms used for WLAN privacy
WLAN Encryption Options
Most secure
AES-CCMP/WPA2 They are resistant to all
known crypto-analysis
Believed secure
TKIP and WPA patch
to They offer defense
WEP against currently known
attacks
Weak security
WEP They can be cracked by
analyzing a sufficient
amount of data
transmission.
Reference: http://www.convergedigest.com/bp-bbw/bp1.asp?ID=465&ctgy=Mesh

Front 250

You need to add a wireless access point to a new Certkiller office. Which additional
configuration step is necessary in order to connect to an access point that has SSID
broadcasting disabled?
A. Configure open authentication on the AP and the client
B. Set the SSID value in the client software to public
C. Set the SSID value on the client to the SSID configured on the AP
D. Configure MAC address filtering to permit the client to connect to the AP
E. None of the above

Back 250

Answer: C

Front 251

Which of the following data network would you implement if you wanted a wireless
network that had a relatively high data rate, but was limited to very short
distances?
A. Broadband personal comm. Service (PCS)
B. Broadband circuit
C. Infrared
D. Spread spectrum
E. Cable
F. None of the above

Back 251

Answer: C

Hint 251

Explanation:
A good example of the range of an infrared is a television remote control or a garage door
opener. Infrared networks are capable of high data rates, but they are limited in the
distance between the infrared points, and also by the fact that a line of sight between the
nodes is usually required.
Incorrect Answers:
A, D: Although these are both wireless methods, the data rate capabilities are somewhat
limited, especially when compared to infrared links.
B, E: Although these are both capable of relatively high data rates, they do not use
wireless technology

Front 252

You need to troubleshoot an interference issue with the Certkiller wireless LAN.
Which two devices can interfere with the operation of this network because they
operate on similar frequencies? (Choose two)
A. Microwave oven
B. AM radio
C. Toaster
D. Copier
E. Cordless phone
F. IP phone
G. I-pod

Back 252

Answer: A, E

Front 253

You need to create a security plan for the Certkiller network. What should be part
of a comprehensive network security plan?
A. Delay deployment of software patches and updates until their effect on end-user
equipment is well known and widely reported
B. Minimize network overhead by deactivating automatic antivirus client updates
C. Encourage users to use personal information in their passwords to minimize the
likelihood of passwords being forgotten
D. Physically secure network equipment from potential access by unauthorized
individuals
E. Allow users to develop their own approach to network security
F. None of the above

Back 253

Answer: D

Hint 253

Explanation:
Computer systems and networks are vulnerable to physical attack; therefore, procedures
should be implemented to ensure that systems and networks are physically secure.
Physical access to a system or network provides the opportunity for an intruder to
damage, steal, or corrupt computer equipment, software, and information. When
computer systems are networked with other departments or agencies for the purpose of
sharing information, it is critical that each party to the network take appropriate measures
to ensure that its system will not be physically breached, thereby compromising the entire
network. Physical security procedures may be the least expensive to implement but can
also be the most costly if not implemented. The most expensive and sophisticated
computer protection software can be overcome once an intruder obtains physical access
to the network

Front 254

As the Certkiller network security administrator, you are concerned with the
various possible network attacks. Which type of attack is characterized by a flood of
packets that are requesting a TCP connection to a server?
A. Trojan Horse
B. Reconnaissance
C. Denial of Service
D. Brute Force
E. Virus
F. None of the above

Back 254

Answer: C

Hint 254

Explanation:
A denial-of-service attack (DoS attack) is an attempt to make a computer resource
unavailable to its intended users. Although the means to, motives for and targets of a DoS
attack may vary, it generally comprises the concerted, malevolent efforts of a person or
persons to prevent an Internet site or service from functioning efficiently or at all,
temporarily or indefinitely. Among these are Network connectivity attacks.
These attacks overload the victim with TCP packets so that its TCP/IP stack is not able to
handle any further connections, and processing queues are completely full with nonsense
malicious packets. As a consequence of this attack, legitimate connections are denied.
One classic example of a network connectivity attack is a SYN Flood

Front 255

The Certkiller administrator is concerned with enhancing network security. To do
this, what are two recommended ways of protecting network device configuration
files from outside security threats on the network? (Choose two)
A. Use a firewall to restrict access from the outside to the network devices
B. Allow unrestricted access to the console or VTY ports
C. Prevent the loss of passwords by disabling encryption
D. Always use Telnet to access the device command line because its data is automatically
encrypted
E. Use SSH or another encrypted and authenticated transport to access device
configurations
F. Use easy to remember passwords so that they are not forgotten

Back 255

Answer: A, E

Hint 255

Explanation:
Whenever the trusted (inside) part of the network connects to an untrusted (outside, or
internet) network, the use of a firewall should be implemented to ensure only legitimate
traffic is allowed within the enterprise. SSH is a secure alternative to telnet that encrypts
the traffic so that data carried within can not be "sniffed." It is always recommended to
use SSH over telnet whenever possible.

Front 256

You want to enable telnet access to a Certkiller router as securely as possible. Which
of the following commands would you execute if you wanted to enable others to
establish a telnet session on a Cisco router?
A. Certkiller 1(config)# line console 0
Certkiller 1(config-if)# enable password Certkiller
B. Certkiller 1(config)# line vty 0
Certkiller 1(config-line)#enable password Certkiller
C. Certkiller 1(config)# line vty 0
Certkiller 1(config-line)#enable secret Certkiller
Certkiller 1(config-line)# login
D. Certkiller 1(config)# line console 0
Certkiller 1(config-line)#enable secret Certkiller
Certkiller 1(config-line)#login
E. Certkiller 1(config)#line console 0
Certkiller 1(config-line)# password Certkiller
Certkiller 1(config-line)#login
F. Certkiller 1(config)#line vty 0
Certkiller 1(config-line)#password Certkiller
Certkiller 1(config-line)#login

Back 256

Answer: F

Hint 256

Explanation:
Telnet sessions use virtual terminal sessions, which are configured under the "line vty"
portion of the configuration. There are 5 total vty sessions that can be configured,
numbered 0-4. In order to be prompted for a password, one must be configured. Choice F
gives the 3 commands needed to allow a single telnet session.
Incorrect Answers:
A, B, C, D. The telnet password needs to be configured in addition to the enable
password. Without the initial password configured, users that try to telnet to the router
will receive a "password required, but none set" message.
D, E. Telnet uses VTY ports, not the console port

Front 257

You want to increase the security in the Certkiller network. What are the two
security appliances that can be installed in this network? (Choose two)
A. SDM
B. ATM
C. IDS
D. IOX
E. IPS
F. IOS
G. FR

Back 257

Answer: C, E

Front 258

Certkiller University has a small campus where 25 faculty members are located. The
faculty offices and student computers are currently on the same network. The
faculty is concerned about students being able to capture packets going across the
network and obtain sensitive material. What could a network administrator do to
protect faculty network traffic from student connections?
A. Install anti-virus software on the student computers.
B. Put the faculty computers in a separate VLAN.
C. Power down the switches that connect to faculty computers when they are not in use
D. Remove the student computers from the network and put them on a peer-to-peer
network.
E. Create an access list that blocks the students from the Internet where the hacking tolls
are located.
F. None of the above

Back 258

Answer: B

Hint 258

Explanation:
Main Functions of a VLAN:
1. The VLAN can group several broadcast domains into multiple logical subnets.
2. You can accomplish network additions, moves, and changes by configuring a port into the
appropriate VLAN.
1. You can place a group of users who need high security into a VLAN so that no users outside f
the VLAN can communicate with them.
2. As a logical grouping of users by function, VLANs can be considered independent from heir
physical or geographic locations.
3. VLANs can enhance network security.
4. VLANs increase the number of broadcast domains while decreasing their size

Front 259

What are three valid reasons to assign ports on VLANs on a new Certkiller LAN
switch? (Choose three)
A. To make VTP easier to implement
B. To isolate broadcast traffic
C. To increase the size of the collision domain
D. To allow more devices to connect to the network
E. To logically group hosts according to function
F. To increase network security

Back 259

Answer: B, E, F

Hint 259

Explanation:
Main Functions of a VLAN (see previous question):
1. The VLAN can group several broadcast domains into multiple logical subnets.
2. You can accomplish network additions, moves, and changes by configuring a port into the
appropriate VLAN.
1. You can place a group of users who need high security into a VLAN so that no users outside f
the VLAN can communicate with them.
2. As a logical grouping of users by function, VLANs can be considered independent from heir
physical or geographic locations.
3. VLANs can enhance network security.
4. VLANs increase the number of broadcast domains while decreasing their size.

Front 260

Of the following choices below, only three could be used as WAN encapsulation
methods, as opposed to LAN encapsulation. Which three are they? (Choose three)
A. FDDI
B. HDLC
C. Frame Relay
D. PPP
E. Token Ring
F. Ethernet
G. VTP

Back 260

Answer: B, C, D

Front 261

What can the Certkiller network administrator utilize by using PPP (Point to Point
Protocol) as the Layer 2 encapsulation? (Choose three)
A. Compression
B. QOS
C. Sliding windows
D. VLAN support
E. Authentication
F. Multilink support

Back 261

Answer: A, E, F

Front 262

You need to establish a point to point circuit between a Cisco router and a Juniper
router on the Certkiller network. You are having difficulty in establishing this serial
link between a Cisco router and another vendor. Both routers are configured for
HDLC encapsulation. Which statements are true regarding this configuration?
(Choose two)
A. HDLC requires a clock rate to be configured on the routers at both ends of the serial
link.
B. The Cisco HDLC frame uses a proprietary "Type" field that may not be compatible
with equipment of other vendors.
C. PPP encapsulation is recommended for serial links between equipment from multiple
vendors.
D. Usernames must be configured at both ends of the HDLC serial link
E. There is a mismatch in the HDLC authentication password configurations.
F. The HDLC vendor type must be enabled on the Cisco router.

Back 262

Answer: B, C

Hint 262

Explanation:
The High Level Data Link Control protocol (HDLC) is the default encapsulation used on
the synchronous serial interfaces of a Cisco router.
HDLC is a Data Link layer protocol used to encapsulate and transmit packets over
point-to-point links. It handles the transfer of data in full duplex, as well as link
management functions. As an OSI standard, many vendors implement the HDLC
protocol in their equipment. Unfortunately, these implementations are usually not
interoperable. The reason is that when the HDLC frame format was defined, it did not
include a field to identify the Network layer protocol that it was framing. As such, the
OSI version of HDLC assumes that any link using HDLC is running only a single
Network layer protocol like IP. Of course, many networks run IP, IPX, and other Layer 3
protocols simultaneously. This has led vendors (including Cisco) to implement HDLC
using a proprietary frame format that includes a type code field, thus allowing the
Network layer protocol within a frame to be properly identified.
The Cisco HDLC frame is illustrated in the figure below

Front 263

You are configuring the serial interface of your Cisco router; which of the following
are valid encapsulation types you can use? (Select all that apply)
A. Token Ring
B. Ethernet
C. HDLC
D. PPP
E. Frame Relay
F. CHAP

Back 263

Answer: C, D, E

Hint 263

Explanation:
HDLC, Frame Relay, and PPP are the most common encapsulation types set for serial
interfaces in a Cisco router. HDLC is often used in point to point circuits with Cisco
routers on each end. HDLC is Cisco proprietary and offers an alternative to PPP.
Incorrect Answers:
A, B. Token Ring and Ethernet aren't encapsulation types used on serial interfaces; they
are types of LAN networks.
F. CHAP is the Challenge Authentication Protocol. It is used for authentication on PPP
links

Front 264

A network administrator needs to configure a serial link between the main office
and a remote location. The router at the remote office is a non-Cisco router.
How should the network administrator configure the serial interface of the main
office router to make the connection?
A. Main(config)# interface serial 0/0
Main(config-if)# ip address 172.16.1.1 255.255.255.255
Main(config-f)# no shut
B. Main(config)# interface serial 0/0
Main(config-if)# ip address 172.16.1.1 255.255.255.255
Main(config-f)# encapsulation ppp
Main(config-if)# no shut
C. Main(config)# interface serial 0/0
Main(config-if)# ip address 172.16.1.1 255.255.255.255
Main(config-f)# encapsulation frame-relay
Main(config-if)# authentication chap
Main(config-if)# no shut
D. Main(config)# interface serial 0/0
Main(config-if)# ip address 172.16.1.1 255.255.255.255
Main(config-f)# encapsulation ietf

Back 264

Answer: B

Hint 264

Explanation:
The default encapsulation on a serial interface is the Cisco proprietary HDLC. When
connecting to routers from another vendor, we will need to use the standards based PPP,
which is correctly defined in choice B.
Incorrect Answers:
A: This is not a correct answer because no encapsulation is defined, so the default HDLC
will be used, which is a Cisco proprietary protocol.
C: CHAP authentication is only used by PPP, not HDLC.
D: IETF itself is not an encapsulation option on an interface; it is used in frame relay
networks, where the encapsulation can be frame relay IETF, but not simply IETF alone

Front 265

While logged into a router you manually shut down the serial 0 interface using the
"shutdown" interface configuration command. You then issue the "show interface
serial 0" command in exec mode. What could you expect the status of the serial 0
interface to be?
A. Serial 0 is up, line protocol is up
B. Serial 0 is up, line protocol is down
C. Serial 0 is down, line protocol is down
D. Serial 0 is down, line protocol is up
E. Serial 0 is administratively down, line protocol is down
F. Serial 0 is administratively down, line protocol is up

Back 265

Answer: E

Hint 265

Explanation:
To bring down an interface for administrative reasons and, as a side effect, remove the
connected router from the routing table, you can use the shutdown interface
subcommand. To enable the interface back up, issue the "no shutdown" configuration
command.
Incorrect Answers:
A. This is the status of a fully operational interface.
B, C. These are the results of line problems or configuration errors.
D, F. These two interface conditions should never be seen.

Front 266

Note: Please refer to the Certkiller Communications scenario.
Your boss Certkiller at PC Certkiller 6 starts communicating with the Certkiller C
internal web server. Her PC sends out an ARP request. How will the other devices
in the network act upon this request?
A. Router Certkiller A will respond with the IP address of the web server Certkiller C.
B. Switch Certkiller B will reply with the MAC address of the server.
C. Router Certkiller 2 will respond with the MAC address of its Fa0/0 interface.
D. Hosts Certkiller 4 and Certkiller 5 will respond that the destination is not on the local
LAN.
E. Router Certkiller 2 will forward the ARP request to router Certkiller A.
F. Switch Certkiller B will block the request since the server is not on the LAN.

Back 266

Answer: C

Front 267

Note: Please refer to the Certkiller Communications scenario.
The Certkiller 6 PC has sent the ARP request, and has now received the ARP reply.
Certkiller 6 now build a packet that will be sent to Certkiller C web server in order to
establish the communication.
What information will be placed in the header of this packet? (Select two)
A. The source address will be the IP address of the Fa0/0 interface of Router Certkiller 2.
B. The source address will be the IP address of the Fa0/0 interface of Switch Certkiller B.
C. The source address will be the IP address of PC Certkiller 6.
D. The destination address will be the IP address of interface Fa0/0 of Router Certkiller 2.
E. The destination address will be the IP address of interface Fa0/0 of Router Certkiller A.
F. The destination address will be the IP address of interface S0/0 of Router Certkiller 2.
G. The destination address will be the IP address of interface S0/0 of Router Certkiller A.
H. The destination address will be the IP address of the Certkiller 3 web server

Back 267

Answer: C, H

Front 268

Note: Please refer to the Certkiller Communications scenario.
The Certkiller 6 PC has sent the ARP request, received an ARP Reply, and sent a
packet to the Certkiller C web server.The Ethernet frame has now been received by
Router Certkiller A and will now be delivered to the local LAN. Consider the
addressing of the Ethernet frame that now has been created by Router Certkiller A.
Which two statements apply in this context? Select two.
A. The source address will be the MAC address of PC Certkiller 6.
B. The source address will be the MAC address of interface S0/0 of router Certkiller A
C. The source address will be the MAC address of interface S0/0 of router Certkiller 2.
D. The source address will be the MAC address of interface Fa0/0 of router Certkiller A
E. The source address will be the MAC address of interface Fa0/0 of router Certkiller 2.
F. The destination address will be the MAC address of Switch Certkiller A port attached
to the Certkiller C web server.
G. The destination address will be the IP address of Switch Certkiller A port attached to
the Certkiller C web server.
H. The destination address will be the MAC address of Switch Certkiller A port attached
to the Certkiller A Fa0/0 interface..
I. The destination address will be the MAC address of the Certkiller C web server

Back 268

Answer: D, I

Front 269

C. The browser track the data by the URL.
D. The TCP port numbers are used to direct the data to the correct application window.
E. None of the above

Back 269

Answer: A

Front 270

What is the bandwidth on the WAN interface of router Certkiller 1?
A. 64 Kbit/sec
B. 32 Kbit/sec
C. 512 Kbit/sec
D. 1544 Kbit/sec
E. 16 Kbit/sec
F. 128 Kbit/sec

Back 270

check pdf

Front 271

The hosts in the LAN are not able to connect to the Internet.
Which commands will correct this issue?
A. Certkiller 1(conf)#interface s0/1
Certkiller 1(conf-if)#ip address 10.11.12.13 255.255.255.252
B. Certkiller 1(conf)#interface s0/1
Certkiller 1(conf-if)#no shutdown
C. Certkiller 1(conf)#interface fa0/0
Certkiller 1(conf-if)#no shutdown
D. Certkiller 1(conf)#interface s0/0
Certkiller 1(conf-if)#ip address 10.11.12.13 255.255.255.252
E. Certkiller 1(conf)#interface fa0/1
Certkiller 1(conf-if)#no shutdown
F. Certkiller 1(conf)#interface s0/0
Certkiller 1(conf-if)#no shutdown

Back 271

check pdf

Front 272

A receiving host on the Certkiller network named CK1 computes the checksum on a
frame and determines that the frame is damaged. The frame is then discarded. At
which OSI layer did this happen?
A. Application
B. Presentation
C. Session
D. Transport
E. Internet
F. Data Link
G. Physical

Back 272

Answer: F

Hint 272

The Data Link layer provides the physical transmission of the data and handles error
notification, network topology, and flow control. The Data Link layer formats the
message into pieces; each called a data frame, and adds a customized header containing
the hardware destination and source address. Protocols Data Unit (PDU) on Datalink
layer is called frame. According to this question the frame is damaged and discarded
which will happen at the Data Link layer

Front 273

What is the purpose of an Address Resolution Protocol (ARP) request message?
A. It creates a session by passing a header with destination Layer 2 address to the
transport layer.
B. It binds the IP address of a host to the network that it is on.
C. It encapsulates the Layer 3 address and then passes the packet to Layer 2.
D. It builds a correlation between an IP address and a MAC address.
E. It provides connectivity and path selection between hosts on a network.
F. None of the above

Back 273

Answer: D

Hint 273

Explanation:
Address Resolution Protocol (ARP) finds the hardware address of a host from a known
IP address. When IP has a datagram to send, it must inform a Network Access protocol,
such as Ethernet or Token Ring, of the destination's hardware address on the local
network. (It has already been informed by upper-layer protocols of the destination's IP
address.) If IP doesn't find the destination host's hardware address in the ARP cache, it
uses ARP to find this information.
This is the protocol operates on Network Layer. Source device sends the ARP broadcast
to resolve the MAC address of destination device.
You can display the ARP table using the "show arp" command

Front 274

What are two characteristics of Telnet? (Choose two.)
A. It requires an enterprise license in order to be implemented.
B. It is more secure than SSH.
C. It is no longer supported on Cisco network devices.
D. It sends data in clear text format.
E. It requires that the destination device be configured to support Telnet connections

Back 274

Answer: D,E

Front 275

Which two practices help secure the configuration utilities on wireless access points from
unauthorized access? (Choose two.)
A. assigning a private IP address to the AP
B. configuring a new administrator password
C. changing the default SSID value
D. configuring traffic filtering
E. changing the mixed mode setting to single mode

Back 275

Answer: B,C

Front 276

The command ip route 192.168.100.160 255.255.255.224 192.168.10.2 20 was issued on
a router. No routing protocols or other static routes are configured on the router. Which
statement is true about this command?
A. The interface with IP address 192.168.10.2 is on this router.
B. The number 20 indicates the number of hops to the destination network.
C. The command sets a gateway of last resort for the router.
D. Packets that are destined for host 192.168.100.190 will be sent to 192.168.10.2.
E. The command creates a static route for all IP traffic with the source address
192.168.100.180.

Back 276

Answer: D

Front 277

Which command is used on a Cisco router named Certkiller 2 to reach the global
configuration mode?
A. Certkiller 2# interface
B. Certkiller 2# configure terminal
C. Certkiller 2# setup
D. Certkiller 2# router
E. Certkiller 2> enable

Back 277

Answer: B

Front 278

In the configuration of NAT, what does the keyword overload signify?
A. If the number of available IP addresses is exceeded, excess traffic will use the
specified address pool.
B. The pool of IP addresses has been exhausted.
C. Multiple internal hosts will use one IP address to access external network resources.
D. When bandwidth is insufficient, some hosts will not be allowed to access network
translation

Back 278

Answer: C

Front 279

WAN data link encapsulation types include which of the following? (Choose two.)
A. Frame Relay
B. T1
C. PPP
D. DSL
E. ISDN

Back 279

Answer: A,C

Hint 279

Explanation:
WAN supports: frame relay, ISDN, LAPB, HDLC, PPP, and ATM.

Front 280

Which command will set the default gateway to 192.168.12.1 on a Cisco switch named
Certkiller 3?
A. Certkiller 3(config)# ip route 192.168.12.1 0.0.0.0
B. Certkiller 3(config)# ip route-default 192.168.12.1
C. Certkiller 3(config)# ip default-network 192.168.12.1
D. Certkiller 3(config)# ip default-gateway 192.168.12.1

Back 280

Answer: D