Which of the following correctly describes an EIGRP feasible successor route?
- The best path
- A suboptimal path
- A backup path
- A shorter path
Explanation: An EIGRP feasible successor is defined as the best alternative loop-free backup path to reach a destination. While the successor is the primary route with the lowest metric and is installed in the routing table, the feasible successor is stored in the topology table but is not used for active forwarding unless the primary path fails.
To qualify as a feasible successor and ensure the path is loop-free, a route must satisfy the feasibility condition: the neighbor's Advertised Distance (the metric for that neighbor to reach the destination) must be less than the Feasible Distance (the current best metric) of the existing successor. The primary advantage of having a feasible successor is that it allows the router to recover immediately from a link failure by promoting the backup route to the routing table without the delay of performing a new route recomputation.
Related exam: Modules 8 – 13: Checkpoint Exam: Network Routing Answers (CCNP ENCOR v9)
