Figure 1 shows the topology for this topic. A successor is a neighboring router that is used for packet forwarding and is the least-cost route to the destination network. The IP address of a successor is shown in a routing table entry right after the word via.
FD is the lowest calculated metric to reach the destination network. FD is the metric listed in the routing table entry as the second number inside the brackets. As with other routing protocols, this is also known as the metric for the route.
Examining the routing table for R2 in Figure 2, notice that EIGRP’s best path for the 192.168.1.0/24 network is through router R3, and that the feasible distance is 3,012,096. This is the metric that was calculated in the previous topic.