Implementing Cisco IP Routing (CCNP ROUTE, legacy) — Question 253

When an EIGRP topology change is detected, what is the correct order of events when there is a FS?

Answer options

• A. The neighbor adjacency is deleted. The feasible route is used. DUAL is notified. Remove all topology entries learned from that neighbor.
• B. DUAL is notified. Remove all topology entries learned from that neighbor. The neighbor adjacency is deleted. Routes enter the Active state and the feasible route is used.
• C. The neighbor adjacency is deleted. Routes enter the Active state and the feasible route is used. DUAL is notified. Remove all topology entries learned from that neighbor.
• D. DUAL is notified. The neighbor adjacency is deleted. Remove all topology entries learned from that neighbor.

Correct answer:

Explanation

The correct answer is B because it correctly outlines the sequence of actions: notifying DUAL first, then removing the topology entries, deleting the neighbor adjacency, and finally entering the Active state while using the feasible route. The other options either misplace the order of these actions or omit critical steps, leading to incorrect behavior in EIGRP operations.