CCNA – EIGRP Questions

1. Refer to the exhibit, when running EIGRP what is required for R1 to exchange routing updates with R3?

AS numbers must be changed to match on all the routers

Loopback interfaces must be configured so a DR is elected

The no auto-summary command is needed on R1 and R3

R2 needs to have two network statements, one for each connected network

In order for R1 to exchange routing updates with R3 when running EIGRP, the AS numbers must be changed to match on all the routers. This is because EIGRP uses Autonomous System (AS) numbers to identify and distinguish between different EIGRP routing domains. By ensuring that the AS numbers are the same on all routers, R1 and R3 will be able to properly communicate and exchange routing updates.

Explanation

In order for R1 to exchange routing updates with R3 when running EIGRP, the AS numbers must be changed to match on all the routers. This is because EIGRP uses Autonomous System (AS) numbers to identify and distinguish between different EIGRP routing domains. By ensuring that the AS numbers are the same on all routers, R1 and R3 will be able to properly communicate and exchange routing updates.

2. A network administrator is troubleshooting an EIGRP problem on a router and needs to confirm the IP addresses of the devices with which the router has established adjacency. The retransmit interval and the queue counts for the adjacent routers also need to be checked. What command will display the required information?

Router# show ip eigrp adjacency

Router# show ip eigrp topology

Router#show ip eigrp interfaces

Router#show ip eigrp neighbors

Below is an example of the show ip eigrp neighbors command. The retransmit interval (Smooth Round Trip Timer – SRTT) and the queue counts (Q count, which shows the number of queued EIGRP packets) for the adjacent routers are listed:

Explanation

Below is an example of the show ip eigrp neighbors command. The retransmit interval (Smooth Round Trip Timer – SRTT) and the queue counts (Q count, which shows the number of queued EIGRP packets) for the adjacent routers are listed:

3. Which type of EIGRP route entry describes a feasible successor?

A primary route,stored in the routing table

A backup route,stored in the routing table

A backup route,stored in the topology table

A primary route,stored in the topology table

Feasible successor is a route whose Advertised Distance is less than the Feasible Distance of the current best path. A feasible successor is a backup route, which is not stored in the routing table but stored in the topology table.

Explanation

Feasible successor is a route whose Advertised Distance is less than the Feasible Distance of the current best path. A feasible successor is a backup route, which is not stored in the routing table but stored in the topology table.

4. Refer to the exhibit. The company uses EIGRP as the routing protocol. What path will packets take from a host on 192.168.10.192/26 network to a host on the LAN attached to router R1?

R3# show ip route Gateway of last resort is not set 192 168.10.0/24 is variably subnetted, 6 subnets, 2 masks D 192.168.10.64/26 [90/2195456] via 192.168.10.9, 00:03:31, Serial0/0 D 192.168.10.0/30 [90/2681856] via 192.168.10.9, 00:03:31, Serial0/0 C 192.168.10.4/30 is directly connected, Serial0/1 C 192.168.10.8/30 is directly connected, Serial0/0 C 192.168.10.192/26 is directly connected, FastEthernet0/0 D 192.168.10.128/26 [90/2195456] via 192.168.10.5,00:03:31, Serial0/1

The path of the packets will be R3 to R2 to R1.

The path of the packets will be R3 to R1 to R2

The path of the packets will be both R3 to R2 to R1 and R3 to R1.

The path of the packets will be R3 to R1

Host on the LAN attached to router R1 belongs to 192.168.10.64/26 subnet. From the output of the routing table of R3 we learn this network can be reach via 192.168.10.9, which is an IP address in 192.168.10.8/30 network (the network between R1 & R3) -> packets destined for 192.168.10.64 will be routed from R3 -> R1 -> LAN on R1.

Explanation

Host on the LAN attached to router R1 belongs to 192.168.10.64/26 subnet. From the output of the routing table of R3 we learn this network can be reach via 192.168.10.9, which is an IP address in 192.168.10.8/30 network (the network between R1 & R3) -> packets destined for 192.168.10.64 will be routed from R3 -> R1 -> LAN on R1.

5. Refer to the exhibit. Based on the exhibited routing table, how will packets from a host within the 192.168.10.192/26 LAN be forwarded to 192.168.10.1?

The router will forward packets from R3 to R2 to R1

The router will forward packets from R3 to R1

The router will forward packets from R3 to R1 to R2

The router will forward packets from R3 to R2 to R1 AND from R3 to R1

From the routing table we learn that network 192.168.10.0/30 is learned via 2 equal-cost paths (192.168.10.9 &192.168.10.5) -> traffic to this network will be load-balancing.

Note: There is a typo in this question because R3 lists the its own IP addresses to 192.168.10.0/30. and 192.168.10.128/26 as the next-hop IP addresses. However we have to choose the best answers based on our understanding even the question output is wrong.

Explanation

From the routing table we learn that network 192.168.10.0/30 is learned via 2 equal-cost paths (192.168.10.9 &192.168.10.5) -> traffic to this network will be load-balancing.

Note: There is a typo in this question because R3 lists the its own IP addresses to 192.168.10.0/30. and 192.168.10.128/26 as the next-hop IP addresses. However we have to choose the best answers based on our understanding even the question output is wrong.