Ip Routing Part 2 Eigrp And Ospf

Front 1

EIGRP features?

Back 1

EIGRP is a classless, advanced distance-vector protocol that supports
IP, IPX, AppleTalk, and now IPv6. EIGRP uses a unique algorithm, called DUAL, to
maintain route information and uses RTP to communicate with other EIGRP routers reliably.

Front 2

how OSPF routers become neighbors and/or adjacent?

Back 2

OSPF routers become neighbors
when each router sees the other’s Hello packets.

Front 3

OSPF NBMA network types?

Back 3

There are five different OSPF network
types that Cisco routers can be configured to support. Two of these are non-proprietary based
(non-broadcast and point-to-multipoint) and three are Cisco proprietary (broadcast, point-topoint,
and point-to-multipoint non-broadcast). Each network type is further characterized by
how routers become adjacent and whether they require the election of a DR/BDR.

Front 4

How to configure single-area OSPF?

Back 4

minimal single-area configuration involves only
two commands: router ospf process-id and network x.x.x.x y.y.y.y area Z.

Front 5

How verify the operation of OSPF

Back 5

There are many show commands that provide useful
details on OSPF, and it is useful to be completely familiar with the output of each: show ip
ospf, show ip ospf database, show ip ospf interface, show ip ospf neighbor, and
show ip protocols.

Front 6

What four routed protocols are supported by EIGRP?

Back 6

IPX, IP, Applae Talk, IPv6

Front 7

When is redistribution required for EIGRP?

Back 7

Redistribution is required when more than one EIGRP session or process is running and
they are identified with different ASNs. Redistribution shares topology information
between EIGRP sessions.

Front 8

What command would be used to enable EIGRP with an autonomous system number of 300?

Back 8

router eigrp 300

Front 9

What command will tell EIGRP that it is connected to network 172.10.0.0?

Back 9

network 172.10.0.0

Front 10

What type of EIGRP interface will neither send nor receive Hello packets?

Back 10

Passive interface

Front 11

Write the command that will enable OSPF process 101 on a router.

Back 11

router ospf 101

Front 12

Write the command that will display details of all OSPF routing processes enabled on a router.

Back 12

show ip ospf

Front 13

Write the command that will display interface-specific OSPF information.

Back 13

show ip ospf interface

Front 14

Write the command that will display all OSPF neighbors.

Back 14

show ip ospf neighbor

Front 15

Write the command that will display all different OSPF route types that are currently
known by the router.

Back 15

show ip ospf database

Front 16

Your company is running IGRP using an AS of 10. You want to configure EIGRP on the network
but want to migrate slowly to EIGRP and don’t want to configure redistribution. What
command would allow you to migrate over time to EIGRP without configuring redistribution?
A. router eigrp 11
B. router eigrp 10
C. router eigrp 10 redistribute igrp
D. router igrp combine eigrp 10

Back 16

B. If you enable EIGRP on a router with the same autonomous system (AS) number, EIGRP
will automatically redistribute IGRP into EIGRP. You will see the IGRP injected routes as
external (EX) routes with an EIGRP AD of 170. This is a nice feature that lets you migrate
slowly to EIGRP with no extra configuration.

Front 17

Which EIGRP information is held in RAM and maintained through the use of Hello and
update packets? (Choose two.)
A. Neighbor table
B. STP table
C. Topology table
D. DUAL table

Back 17

A, C. EIGRP holds three tables in RAM: neighbor, topology, and routing. The neighbor and
topology tables are built and maintained with the use of Hello packets.

Front 18

Which of the following describe the process identifier that is used to run OSPF on a router?
(Choose two.)
A. It is locally significant.
B. It is globally significant.
C. It is needed to identify a unique instance of an OSPF database.
D. It is an optional parameter required only if multiple OSPF processes are running on
the router.
E. All routes in the same OSPF area must have the same Process ID if they are to exchange
routing information.

Back 18

A, C. The Process ID for OSPF on a router is only locally significant and you can use the
same number on each router, or each router can have a different number—it just doesn’t
matter. The numbers you can use are from 1 to 65,535. Don’t get this confused with area
numbers, which can be from 0 to 4.2 billion

Front 19

Where are EIGRP successor routes stored?
A. In the routing table only
B. In the neighbor table only
C. In the topology table only
D. In the routing table and neighbor table
E. In the routing table and the topology table
F. In the topology table and the neighbor table

Back 19

E. Successor routes are going to be in the routing table since they are the best path to a remote
network. However, the topology table has a link to each and every network, so the best answer
is topology table and routing table. Any secondary route to a remote network is considered a
feasible successor, and those routes are only found in the topology table and used as backup
routes in case of primary route failure

Front 20

Which command will display all the EIGRP feasible successor routes known to a router?
A. show ip routes *
B. show ip eigrp summary
C. show ip eigrp topology
D. show ip eigrp adjacencies
E. show ip eigrp neighbors detail

Back 20

C. Any secondary route to a remote network is considered a feasible successor, and those
routes are only found in the topology table and used as backup routes in case of primary route
failure. You can see the topology table with the show ip eigrp topology command.

Front 21

You get a call from a network administrator who tells you that he typed the following into
his router:
Router(config)#router ospf 1
Router(config-router)#network 10.0.0.0 255.0.0.0 area 0
He tells you he still can’t see any routes in the routing table. What configuration error did the
administrator make?
A. The wildcard mask is incorrect.
B. The OSPF area is wrong.
C. The OSPF Process ID is incorrect.
D. The AS configuration is wrong.

Back 21

A. The administrator typed in the wrong wildcard mask configuration. The wildcard should
have been 0.0.0.255.
7. C, D, F. RIPv1 and IGRP are true distance-vector routing protocols and can’t do much,
really—except build and maintain routing tables and use a lot of bandwidth! RIPv2, EIGRP,
and OSPF build and maintain routing tables, but they also provide classless routing, which
allows for VLSM, summarization, and discontiguous networking.

Front 22

Which of the following protocols support VLSM, summarization, and discontiguous networking?
(Choose three.)
A. RIPv1
B. IGRP
C. EIGRP
D. OSPF
E. BGP
F. RIPv2

Back 22

C, D, E. Loopback interfaces are created on a router, and the highest IP address on a loopback
(logical) interface becomes the RID of the router but has nothing to do with areas and is optional,
so option A is wrong. The numbers you can create an area with are from 0 to 4,294,967,295—
option B is wrong. The backbone area is called area 0, so option C is correct. All areas must connect
to area 0, so option E is correct. If you have only one area, it must be called area 0, so option
F is incorrect. This leaves option D, which must be correct; it doesn’t make much sense, but it is
the best answer.

Front 23

Which of the following are true regarding OSPF areas? (Choose three.)
A. You must have separate loopback interfaces configured in each area.
B. The numbers you can assign an area go up to 65,535.
C. The backbone area is also called area 0.
D. If your design is hierarchical, then you don’t need multiple areas.
E. All areas must connect to area 0.
F. If you have only one area, it must be called area 1.

Back 23

A, C. No DR is assigned on any type of point-to-point link. No DR/BDR is assigned on the
NBMA point-to-multipoint due to the hub/spoke topology. DR and BDR are elected on broadcast
and non-broadcast multi-access networks. Frame Relay is a non-Broadcast Multi-Access
(NBMA) network by default.

Front 24

Which of the following network types have a designated router and a backup designated router
assigned? (Choose two.)
A. Broadcast
B. Point-to-point
C. NBMA
D. NBMA point-to-point
E. NBMA point-to-multipoint

Back 24

A, C. No DR is assigned on any type of point-to-point link. No DR/BDR is assigned on the
NBMA point-to-multipoint due to the hub/spoke topology. DR and BDR are elected on broadcast
and non-broadcast multi-access networks. Frame Relay is a non-Broadcast Multi-Access
(NBMA) network by default.

Front 25

A network administrator needs to configure a router with a distance-vector protocol that
allows classless routing. Which of the following satisfies those requirements?
A. IGRP
B. OSPF
C. RIPv1
D. EIGRP
E. IS-IS

Back 25

D. In this question, we’re calling EIGRP just plain old distance vector. EIGRP is an “advanced”
distance-vector routing protocol, sometimes called a hybrid routing protocol because it uses the
characteristics of both distance-vector and link-state routing protocols.

Front 26

You need the IP address of the devices with which the router has established an adjacency.
Also, the retransmit interval and the queue counts for the adjacent routers need to be checked.
What command will display the required information?
A. show ip eigrp adjacency
B. show ip eigrp topology
C. show ip eigrp interfaces
D. show ip eigrp neighbors

Back 26

D. The show ip eigrp neighbors command allows you to check the IP addresses as well as
the retransmit interval and queue counts for the neighbors that have established an adjacency.

Front 27

For some reason, you cannot establish an adjacency relationship on a common Ethernet link
between two routers. Looking at the output below, what is the cause of the problem?
RouterA#
Ethernet0/0 is up, line protocol is up
Internet Address 172.16.1.2/16, Area 0
Process ID 2, Router ID 172.126.1.1, Network Type BROADCAST, Cost: 10
Transmit Delay is 1 sec, State DR, Priority 1
Designated Router (ID) 172.16.1.2, interface address 172.16.1.1
No backup designated router on this network
Timer intervals configured, Hello 5, Dead 20, Wait 20, Retransmit 5
RouterB#
Ethernet0/0 is up, line protocol is up
Internet Address 172.16.1.1/16, Area 0
Process ID 2, Router ID 172.126.1.1, Network Type BROADCAST, Cost: 10
Transmit Delay is 1 sec, State DR, Priority 1
Designated Router (ID) 172.16.1.1, interface address 172.16.1.2
No backup designated router on this network
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5

A. The OSPF area is not configured properly.
B. The priority on RouterA should be set higher.
C. The cost on RouterA should be set higher.
D. The Hello and Dead timers are not configured properly.
E. A backup designated router needs to be added to the network.
F. The OSPF Process ID numbers must match.

Back 27

D. The Hello and Dead timers must be set the same on two routers on the same link or they
will not form an adjacency (relationship). The default timers for OSPF are 10 seconds for the
Hello timer and 40 seconds for the Dead timer.

Front 28

Which is true regarding EIGRP successor routes? (Choose two.)
A. A successor route is used by EIGRP to forward traffic to a destination.
B. Successor routes are saved in the topology table to be used if the primary route fails.
C. Successor routes are flagged as “active” in the routing table.
D. A successor route may be backed up by a feasible successor route.
E. Successor routes are stored in the neighbor table following the discovery process.

Back 28

A, D. Successor routes are the routes picked from the topology table as the best route to a remote
network, so these are the routes that IP uses in the routing table to forward traffic to a remote destination.
The topology table contains any route that is not as good as the successor route and is considered
a feasible successor, or backup route. Remember that all routes are in the topology table,
even successor routes.

Front 29

Which type of OSPF network will elect a backup designated router? (Choose two.)
A. Broadcast multi-access
B. Non-broadcast multi-access
C. Point-to-point
D. Broadcast multipoint

Back 29

A, B. DR and BDR are elected on broadcast and non-broadcast multi-access networks. Frame
Relay is a non-broadcast multi-access (NBMA) network by default. No DR is assigned on any
type of point-to-point link. No DR/BDR is assigned on the NBMA point-to-multipoint due to
the hub/spoke topology.

Front 30

Which two of the following commands will place network 10.2.3.0/24 into area 0? (Choose two.)
A. router eigrp 10
B. router ospf 10
C. router rip
D. network 10.0.0.0
E. network 10.2.3.0 255.255.255.0 area 0
F. network 10.2.3.0 0.0.0.255 area0
G. network 10.2.3.0 0.0.0.255 area 0

Back 30

B, G. To enable OSPF, you must first start OSPF using a Process ID. The number is irrelevant;
just choose a number from 1 to 65,535 and you’re good to go. After you start the OSPF process,
you must configure any network that you want advertised via OSPF using wildcards and
the area command. Answer F is wrong because there must be a space after the parameter area
and before you list the area number.

Front 31

With which network type will OSPF establish router adjacencies but not perform the DR/BDR
election process?
A. Point-to-point
B. Backbone area 0
C. Broadcast multi-access
D. Non-broadcast multi-access

Back 31

A. No DR is assigned on any type of point-to-point link. No DR/BDR is assigned on the
NBMA point-to-multipoint due to the hub/spoke topology. DR and BDR are elected on broadcast
and non-broadcast multi-access networks. Frame Relay is a non-broadcast multi-access
(NBMA) network by default.

Front 32

What are three reasons for creating OSPF in a hierarchical design? (Choose three.)
A. To decrease routing overhead
B. To speed up convergence
C. To confine network instability to single areas of the network
D. To make configuring OSPF easier

Back 32

A, B, C. OSPF is created in a hierarchical design, not a flat design like RIP. This decreases
routing overhead, speeds up convergence, and confines network instability to a single area
of the network

Front 33

What is the administrative distance of OSPF?
A. 90
B. 100
C. 110
D. 120

Back 33

C. The administrative distance (AD) is a very important parameter in a routing protocol. The lower
the AD, the more trusted the route. If you have IGRP and OSPF running, by default IGRP routes
would be placed in the routing table because IGRP has a lower AD of 100. OSPF has an AD of 110.
RIPv1 and RIPv2 both have an AD of 120, and EIGRP is the lowest, at 90.

Front 34

If routers in a single area are configured with the same priority value, what value does a router
use for the OSPF Router ID in the absence of a loopback interface?
A. The lowest IP address of any physical interface
B. The highest IP address of any physical interface
C. The lowest IP address of any logical interface
D. The highest IP address of any logical interface

Back 34

B. At the moment of OSPF process startup, the highest IP address on any active interface will
be the Router ID (RID) of the router. If you have a loopback interface configured (logical
interface), then that will override the interface IP address and become the RID of the router
automatically.