Cisco CCNA mock exam questions sample test – Question 264

.You are the Cisco administrator for Metroil. One of your assistants has submitted the given diagram as a potential addressing plan for two offices. Both offices use EIGRP as the
routing protocol. You immediately see a problem with the proposal.
Which of the following actions could be a solution? (Choose two. Each correct option is a complete solution.)

A. Execute the no auto-summary command on both routers.
B. Change the network on F0/0 of Router A to 192.168.3.0/24 and change the network on F0/0 of Router B to 192.168.2.0/24.
C. Change the network on F0/0 of Router B to 192.168.1.48/28.
D. Execute the auto-summary command on both routers.

Correct Answer: AB

Explanation:
You should either execute the no auto-summary command on both routers, or change the network on F0/0 of Router A to 192.168.3.10/24 and the network on F0/0 of Router B to
192.168.2.0/24. The exhibit is an example of discontiguous subnets, in which two subnets (192.168.1.16 and 192.168.1.32) of the same major network (192.168.1.0) are separated by
a completely different network (172.16.0.4/30). The no auto-summary command instructs EIGRP to stop automatically summarizing advertised networks to their classful boundaries.
Without the no auto–summary command, EIGRP will automatically summarize these two subnets to 192.168.1.0, and advertise the summary route across the WAN link, losing the
subnet-specific information and causing routing problems. The no auto-summary command stops this behavior, and allows EIGRP to advertise specific subnets.
An alternate solution would be to change the network on F0/0 of Router A to 192.168.3.0/24 and the network on F0/0 of Router B to 192.168.2.0/24. If that were done, the two
networks would be in separate class C networks and auto summarization would not be a problem.
It would not help to change the network on F0/0 of Router B to 192.168.1.48/28. The two networks would still be in the same class C network and the summarization process would
confuse routing.
It would not help to execute the auto-summary command. The command is already in effect by default.
Objective:
Routing Fundamentals
Sub-Objective:
Configure, verify, and troubleshoot EIGRP for IPv4 (excluding authentication, filtering, manual summarization, redistribution, stub)
References:
Cisco > Home > Support > Technology Support > IP > IP Routing >Technology Information>Technology White Paper> Enhanced Interior Gateway Routing Protocol> Auto-
Summarization