Which of the following does the show ip eigrp topology all-links command display?

A. Only feasible successors
B. Only non-feasible successors

C. Both feasible successors and non-feasible successors

D. Both successors and feasible successors

Explanation:
The show ip eigrp topology all-links command displays both the feasible successors and the non-feasible successors. Feasible successors refer to backup routes to a particular destination network.

Routers compute the metric/distance of every route they learn from their EIGRP neighbors. There can be multiple routes to the same destination network. The route with the least metric value to a specific destination network is selected as the best path, or successor, to that network. However, if the successor goes down, the router computes the next best loop-free path to the same destination network, which is called the feasible successor.

Feasible successors must have a reported (or advertised) distance that is less than the feasible distance, or current best metric. The routes that are neither successors nor feasible successors are called non-feasible successors. The feasible successors and the non-feasible successors can be viewed by running the show ip eigrp topology all-links command. Sample output is shown below:

The router at 172.17.3.1 is directly connected to three networks: 172.25.1.0/24, 172.20.2.0/24, and 172.18.2.0/24. The second network, 172.20.2.0/24, is listed as the source of the successor routes to those networks. The connection to the last network, 172.18.2.0/4, can deduced by the fact that the local router uses the Serial1 interface to connect to the two networks that the router at 172.17.3.1 is a successor for. Therefore, that router must be directly connected to the network on the Serial1 interface of the local router.

Objective:
Layer 3 Technologies
Sub-Objective:
Configure and verify policy-based routing

References:
Cisco IOS IP Routing: EIGRP Command Reference > show ip eigrp topology