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186 Cards in this Set

  • Front
  • Back
BGP is what kind of protocol?
Path Vector
OSPF is what kind of protocol?
Link State
RIP is what kind of protocol?
Distance Vector
EIGRP is what kind of protocol?
What is the AD of directly connected routes?
What is the AD of static routes?
What is the AD of EIGRP summary routes?
What is the AD of external BGP routes?
What is the AD of internal EIGRP routes?
What is the AD of IGRP routes?
What is the AD of OSPF routes?
What is the AD of IS-IS routes?
What is the AD of RIP routes?
What is the AD of ODR routes?
What is the AD of external EIGRP routes?
What is the AD of internal BGP routes?
What is the AD of unknown routes?
What is the RIB and what command do you use to view it?
routing information base, viewed with the show ip route command
What is the FIB and what command do you use to view it?
forwarding information base, stored in memory/hardware viewed with the show ip cef command
What is the STP convergence process?
1. Elect the root bridge
2. Each non-root device selects a root port(best path to root bridge - best path is lowest cost; (cost based on bandwidth)
3. For every link, one designated port is selected; again, decision based on cost(bandwidth). Remember, every port on the root bridge is a designated port.
4. All other ports set to blocking - Remember, this is for each VLAN under per VLAN STP (PVST)
What determines the winner of the root bridge election?
lowest bridge ID wins, bridge ID consists of 2 byte priority field, plus a 6 byte mac address, and the VLAN ID
The default STP priority is ______ and can be changed in increments of _______
32768, 4096
The STP tiebreaker process consists of ______, ________, and __________.
lowest cost path to the root device(bandwidth)
lowest sender bridge ID
lowest port ID
Explain the command spanning-tree vlan 7 root primary or secondary
causes switch to look at other devices in topology and sets it either higher if primary and lower than primary but higher than anything else if secondary
What are the STP port states, and what timer is used at each state and for how long?
Blocking - 20 Sec max age
Listening -15 Sec forward delay(processing BPDUs)
Learning - 15 Sec forward delay(placing MAC entries in the MAC table)
Forwarding - forwarding frames
Where and why would you use portfast?
when connected to servers or workstations to bypass STP convergence
Where and why would you use uplinkfast?
used to speed up convergance at an access layer switch when a redundant connection is lost to the distribution layer
When and why would you use backbonefast?
can save on the Max Age timer when there is an indirect link failure(enabled on every switch in the topology)
What are the 802.1w STP port states?
What are the RSTP port roles?
Root port - same as 802.1D
Designated port - same as 802.1D
Alternate port - alternate port for the root port(just think alternate path to the root bridge)
Backup port - backup to the designated port
Note: These new roles help replace the need for UplinkFast and BackboneFast
Key differences of 802.1D and 802.W are now BPDUs in RSTP are used for ______, and topology changes can be sent from __________
all switches
802.1s runs on top of ______
802.1s allows you to create a unique topology per ________
802.1s have switches that all share ______, _____, and ______
region name, revision number, and VLAN mappings to instances

spanning-tree mode mst
spanning-tree mst configuration
revision 1
instance 1 vlan 10-20
instance 2 vlan 21-30
Loopguard is implemented for
The STP loop guard feature provides additional protection against Layer 2 forwarding loops (STP loops). An STP loop is created when an STP blocking port in a redundant topology erroneously transitions to the forwarding state. This usually happens because one of the ports of a physically redundant topology (not necessarily the STP blocking port) no longer receives STP BPDUs. In its operation, STP relies on continuous reception or transmission of BPDUs based on the port role. The designated port transmits BPDUs, and the non-designated port receives BPDUs.

%SPANTREE-2-LOOPGUARD_BLOCK: Loop guard blocking port FastEthernet0/24 on
UDLD is implemented for
often enabled by default for fibre optic interfaces
Occurs when traffic sent by a local device is received by its neighbor, but traffic from the neighbor is not received by the local device

* Fiber strands in a fiber-optic interface are misconnected
* One of the interfaces cannot send or receive traffic
* One of the interface is down and the other is up
* One of the fiber strands in cable is disconnected
BPDUGuard is implemented for
enforces the STP domain borders and keeps the active topology predictable
PortFast ports could experience a temporary Layer 2 loop if a switch replaces the server or workstation
BPDUGuard immediately error disables the port when a BPDU is detected
Root guard is implemented for ...
enforces the Layer 2 STP topology, if a port receives a superior BPDU it moves the port to the root-inconsistent STP state. An ISP could use this to guard against a customer switch inadvertently becoming the root device
BPDUFilter is implemented for ...
Prevents BPDUs from being sent on a port;also causes the switch to ignore BPDUs received(DANGEROUS)
Can be used globally in conjunction with PortFast - when the PortFast port receives a BPDU, it will lose its PortFast status
Storm Control does the following
designed to protect the network against a broadcast storm

* Monitors traffic by traffic type in 1 second intervals
* If traffic of a certain type(broadcast, unicast, multicast) hits the threshold, all incoming traffic is stopped on the port
* Some hardware platforms support a broadcast suppression feature in hardware
What are the different trunking modes and what are the properties of each?
* on(switchport mode trunk) - forces the interface to trunk, and sends DTP frames
* off(swithport mode access) - forces the interface to access mode (non-trunk)
* desirable(switchport mode dynamic desirable) - willing to trunk and sends DTP frames
* auto(switchport mode dynamic auto) - willing to trunk but does not send DTP frames
* nonegotiate(switchport nonegotiate) - used with the ON mode - stops DTP (no frames sent)
In half-duplex mode these errors are normal.
1% ration of errors to total traffic is acceptable
What Cisco proprietary protocol and what RFC provides layer 3 redundancy?
True or False
HSRP provides a Virtual MAC address and IP address to clients
True or False
HSRP uses multiple concurrent routers for forwarding
The Default HSRP priority is
True or False
In HSRP priority the the higher priority wins
What HSRP technology allows you to take over as active forwarder?
standby preempt
HSRP exchanges hellos over what address/port
Give an example of when you would use HSRP groups
A device can be active for one group and standby for another
Since HSRP hellos are sent over LAN interfaces, how does HSRP konw to failover in the event of a WAN interface dropping?
Decrement the priority if there is a failure, requires HSRP preempt.
If the HSRP standby address is reported as a duplicate, what is this a possible problem with?
STP, EtherChannel, or duplicate frame issue.
HSRP state flapping is caused by
HSRP not receiving hellos, or a physical layer problem
What could cause HSRP to fail to recognize its peer?
Physical layer problem, or VTP issue
What could cause an HSRP state change with error?
If Virtual MAC/HSRP issue, if not STP or physical layer, or two active routers.
HSRP state changes on multicast stub
common cause deals with the non-Reverse Path Forwarding traffic that the non-designated router(DR) sees, an access-list on the non-DR is needed
HSRP asymemetric routing
can result in excessive MAC flooding, adjust MAC aging timer, or ARP timeout, or both
HSRP Virtual IP reported as different
interVLAN leakage because of bridging loops in the switch
HSRP causes MAC violation with port security
force the device to use the burned in MAC instead of virtual
HSRP - Interface hardware cannot support multiple groups
force the device to use the burned in MAC instad of the virtual
What L3 redundancy standard has round robin load balancing built in?
True or False
GLBP is an open standard
What standard uses an active virtual gateway for responding with MAC addresses pointing to other available default gateways?
GLBP uses what adrdress/port for hellos? What frequency? 3222
3 seconds
True or False
VRPP is a Cisco proprietary method to provide L3 redundancy
False - RFC 3768
In VRPP a group of devices is called a _______
Virtual Router Group
The IP of _________ is used in VRPP instead of a seperate router address like HSRP.
VRM - Virtual Router Master
In NAT Global addresses are
outside the network
In NAT Local addresses are
inside the network
In NAT, an address that is assigned to the host inside the network is called
inside local
In NAT, a non-private address that represents the inside host
inside global
In NAT, an IP address of an outside host as it appears in the inside network
outside local
In NAT, an IP address assigned to a host on the outside network
outside global
In order to receive time from an authoritative time server type this command.
ntp server
In NTP some platforms possess a battery-powered hardware clock, use this command to run it
ntp update-calendar
For a router to PROVIDE the time use this command
ntp master [stratum]
The stratum is a measure of how close to the time to the time source, 1 indicates you are the time source, the default is 8
In NTP if you want to be updates from another device use this command
ntp peer(symmetric active mode)
In NTP if you want everyone on the same L3 network to get the time use this command
ntp broadcast
DHCP configuration requires these three items
pool, address space, and exclusions
To statically assign a DHCP address use one of these two methods
ip dhcp pool MANUAL
hardware-address 02c7.f800.0422
client-name HWTO-CUJO

ip dhcp pool MANUAL2
origin file tftp://
WCCP takes client web requests and redirects the request to a
Cisco Content Engine
WCCP defaults to version
True or False
WCCP supports IPv4 and IPv6
WCCP v1 supports the following ports
True or False
WCCP v1 only supports one router per content engine cluster.
How many content engines and how many routers in a service group?
WCCP can use multicast for communication as long as the TTL is 16 or less.
False, 15 or less.
WCCP uses what methods to redirect traffic.
GRE or L2
For L2, the content engine and the router must be on the same subnet, MAC address reqriting handles the redirect.
To enable WCCP on an interface use this command.
ip wccp web-cache
int fa0/0(interface in which web client resides)
ip wccp web-cache redirect in
To force syslog messages to the console
no logging on
OSPF Network Type 1
Router links and state
Flooded in the area of origination
OSPF Network Type 2
Generated by the DR
Lists all attached routers
Flooded in the area of origination
OSPF Network Type 3
Network Summary
Generated by ABRs
Sent into an area to advertise prefixes in other areas
Flooded throughout the AS
OSPF Network Type 4
ASBR Summary
Generated by ABR
Advertised the ASBR
Flooded throughout the AS
OSPF Network Type 5
AS External
Generated by the ASBR
Advertises external destination
Flooded throught the AS
OSPF Network Type 7
NSSA External
Generated by the ASBR in a not-so-stubby-area
Advertises external destination
What LSA types does the OSPF area type "stub" block?
blocks 4,5
totally stubby
blocks 3,4,5
What is an OSPF not-so-stubby area?
A type of stub area in the Open Shortest Path First (OSPF) protocol that can import autonomous system (AS) external routes and send them to the backbone, but cannot receive AS external routes from the backbone or other areas
totally not so stubby
Just like NSSA but it does not allow type 3 or type 4 into area
In OSPF to summarize from one area to another use this command
area range
In OSPF you can summarize external prefixes using this command
True or False
In an OSPF point to point network type there is a DR and BDR
The OSPF Broadcast network type a DR/BDR is elected based on
highest IP address
highest priority, default is 1
The OSPF network type NBMA require what to form an adjacency
manual neighbor configuration
True or False
The OSPF network type point to multipoint there is not a DR/BDR
What is needed to form an adjacency in the OSPF network type of point to multipoint non-broadcast.
No DR/BDR, manual configuration of neighbors
What could cause the OSPF neighbor list to be empty?
Not properly configured on interfaces
L1 or L2 issue
Passive interface
Access list blocking
Error in L3 interface config
Hello or Dead timer mismatch
Authentication configuration error
Area ID mismatch
Stub flag mismatch
secondary IP addressing issue
incorrect network type configuration
What could cause an OSPF stuck in attempt state?
Misconfigured neighbor statement
Unicast non-functional in NBMA environment
What could cause an OSPF stuck in INIT state?
Hellos being blocked in one direction
Multicast nonfunctional on one side
Authentication only on one side
Broadcast keyword missing from map command
What would cause an OSPF stuck in TWO-WAY state?
Priority of 0 on all routers
Neighbor stuck in EXSTART
Mismatched MTU
Duplicate Router IDs
Broken unicast connectivity
What would cause an OSPF stuck in LOADING state?
Mismatched MTU
Corrupted link-state request
BGP uses what TCP port for its transport
eBGP is assumed to be directly connected, if not, use the following command
EIGRP uses the following metrics
Feasible Distance is
The cost between the local router and the destination prefix. Consists of the cost of the next hop, added to the cost that the next hop is advertising to the local router.
In EIGRP the successor is
the best(lowest cost) route to the destination
In EIGRP the feasible successor is
the 2nd best route, but the next hop must have an AD less than the current FD of the successor
When you use EIGRP stubs
remote devices will not query stubs
The three steps of setting up PBR
Identify the Route Map used for policy routing
int fa/0
ip policy route-map MAP_NAME

Build the route map
Match the traffic based on:
Access List - protocol or application
Access List - particular source and/or destination
Layer 3 packet length

Set the behavior
Next Hop
Output interface
Default next hop or interface
The three steps of setting up MQC
1. Identify traffic "buckets"
class map

2. Dictate policy - what happens to the traffic?

3. Assign the configuration

class-map CM_WEB
match protocol http

policy-map PM_CBWFQ
class CM_WEB
bandwidth percent 10

int fa0/0
service-policy output PM_CBWFQ
NBAR has two jobs
Protocol analysis
Traffic classification for QoS
To enable NBAR
ip nbar protocol-discovery

class-map CM_NBAR
match protocol http
CoS 7
CoS 6
CoS 5
Voice Bearer(Critical)
CoS 4
CoS 3
Call Signalling(flash)
CoS 2
High Priority Data(Immediate)
CoS 1
Medium Priority Data(immediate)
CoS 0
Best Effort(routine)
In the ToS byte how many bits were originally used for IP Precendence
In The ToS byte how many bits are used for DSCP
In the ToS byte how what are the last two bits used for
Flow Control
The DSCP PHB class selector is used for
Backwards Compabtibility
Last three bits are set to 000
The default DSCP PHB is used for
Best effort service
The Assured Forwarding PHB is used for
guaranteed bandwidth services
001, 010, 011, or 100 initial bit settings
The expedited forwarding PHB is used for
First three bits are 101
QoS policy propagation through BGP can classify packets based on these three things
access lists
BGP community lists
BGP AS paths
What queuing method can lead to queue starvation?
Priority Queuing
What queuing method can lead to latency for voice?
Custom queuing
What queuing method does not accommodate for for bandwidth reservations?
What queuing method adds a priority queue to CBWFQ?
What queuing method guarantees prioritized BW and it is policed?
What queuing method resolves issues caused by sliding windows and tail drop?(global synchronization)
What queuing method uses min threshold(start random drops) and max threshold(tail drops start here)?
Policing and shaping use these three similar methods to control traffic.
Policing and shaping main four differences are
shaping buffers excess traffic
policing drops it
policing can also re-mark excess traffic and send it
shaping is outbound only, policing is outbound and inbound
Police or Shape
Rate limit when physical media is higher than the bandwidth service paid for
Police or Shape
Limiting certain applications in the network
Police or Shape
Remarking excess traffic before sending
Bc is
normal burst size - amount of packets forwarded each timing interval Tc
To calculate CIR use the following formula
8000 Bits (Bc) with 250 millisecond (Tc) - the CIR is 8000/.25 = 32 Kbps
To prevent and manage congestion in ATM or Frame-Relay networks use this technology.
To allow customer to regulate traffic locally to the provider use this technology
What DLCIs can be assigned to a frame-relay circuit?
0-15 and 1008-1023 are reserved
The three LMI signaling options are
Q.933 - Annex A
What is does the LMI status of active signify?
Healthy on each end and data can be transferred
What does the LMI status inactive signify?
The local connection is healthy, but the remote side is not
What does the LMI status deleted signify?
No LMI, or the DLCI was deleted from the switch
In frame-relay full mesh what formula can you use to determine the number of circuits needed?
n is the number of nodes
5 routers
Phase II of DMVPN was create for what reason
To permit dynamic creation of spoke to spoke tunnels
In DMVPN multipoint GRE is used for
transporting data and routing information from the hub to multiple potential spokes
In DMVPN next hop resolution protocol(NHRP) is used
to dynamically register addresses from the spokes; a spoke can check in with the hub to connect directly with another spoke
Four advantages of DMVPN are
Hubs to do not require separate GRE interfaces and crypto maps for each spoke

Additional spokes need no hub configuration

Spokes can use dynamic, external facing addresses

Dynamic routing protocols may be used over the infrastructure
To create an IPSec profile for DMVPN to protect the GRE tunnel use this command
crypto ipsec profile
To configure the two phases of IPSec for use in DMVPN use these commands
crypto isakmp policy
crypto ipsec transform
To create the mGRE tunnel for DMVPN use the following command
tunnel mode gre multipoint
The class D range reserved for multicast is -
Multicast range reserved for routing protocols and other maintenance functions(local link scope)
local network control block
Reserved for internet applications like NTP -
internetwork control block
GLOP multicast
233.AS_Value.local assignment
Reserved for use in organizations - administratively scoped
The top 256 in each admin scope are reserved for scope relative addresses, for example, reserved for DHCPv4
What protocol is host to router that allows hosts to request to join to a multicast group?
IGMP v2 added these new features
Leave group
Router messages - general query, group-specific query
membership report - sent when a host wants to join the group or in response to a membership query; the address of the message is the group that is desired
IGMP v3 added these new features
Members can express INCLUDE and EXCLUDE filter requests
Groups and source specific query modified to include a request for a specific source
What multicast technology radiates traffic from a source using a distribution tree?
What notation signifies source-based(shortest path trees SPTs)?
What notation signifies a shared tree in which traffic is sent through an RP?
What PIM mode uses flood and prune, and uses a source based approach(SPT)? (S,G)
Dense Mode
What PIM mode uses an explicit join approach, and supports SPT and Shared trees? (*,G)
Sparse Mode
What PIM mode was created to enable Auto-RP technology?
The designated router in PIM wins the election based on
The highest IP address
Reference to moving traffic away from the source, instead of to a destination

The primary loop prevention mechanism in multicast

Use the unicast IP routing table to determine the upstream path to the source

If the traffic arrives on an interface that the unicast routing table does not consider upstream, the traffic is dropped
Bidirectional PIM
Variation on the PIM-SM mode - addresses issues for groups with large numbers of sources - less overhead due to the large number of sources

Forwarding of traffic is done solely by (*.G) mechanisms

Keeps the technology loop free

Responsible for forwarding the appropriate mutlicast traffic upstream

The DF is elected using the best unicast route to the RP
Bidirectional PIM
Reference to moving traffic away from the source, instead of to a destination

The primary loop prevention mechanism in multicast

Use the unicast IP routing table to determine the upstream path to the source

If the traffic arrives on an interface that the unicast routing table does not consider upstream, the traffic is dropped
Multicast Reverse Path Forwarding Check