Implementing and Operating Cisco Enterprise Network Core Technologies (ENCOR) — Question 894

A network engineer is configuring OSPF on a router. The engineer wants to prevent having a route to 172.16.0.0/16 learned via OSPF in the routing table and configures a prefix list using the command ip prefix-list OFFICE seq 5 deny 172.16.0.0/16. Which two additional configuration commands must be applied to accomplish the goal? (Choose two.)

Answer options

• A. ip prefix-list OFFICE seq 10 permit 0.0.0.0/0 le 32
• B. distribute-list prefix OFFICE in under the OSPF process
• C. distribute-list OFFICE in under the OSPF process
• D. distribute-list OFFICE out under the OSPF process
• E. ip prefix-list OFFICE seq 10 permit 0.0.0.0/0 ge 32

Correct answer: A, B

Explanation

The correct options A and B ensure that all other routes are allowed while specifically blocking the 172.16.0.0/16 route from being learned by OSPF. Option C does not specify a prefix list and cannot achieve the goal, while option D would apply the filter in the outbound direction, which is not the desired configuration for this scenario.