The following show ip eigrp topology output indicates that a route is undergoing recomputation:
A 192.168.13.0/24, 1 successor, FD is Inaccessible, Q
The letter A indicates a route that is in the active state. A route is in the active state when a successor becomes unavailable and no feasible successor exists. When a route transitions from the passive state to the active state, the router will send multicast query packets to its neighbors to find an alternate route to the destination network. The route will remain in the active state until replies are received for each of the neighbor queries. When all queries have been received, the router will calculate the best route to the destination network. If a neighbor router does not respond before the active timer expires, the querying router will become stuck in active (SIA) and the neighbor router will be removed from the querying router's neighbor table. A router that is SIA because of missing replies will generate %DUAL-3-SIA debug error messages.
The letter P indicates a route that is in the passive state. A route is in the passive state if it has connectivity to the successor, which is the best nexthop router to a destination network. If all of the routes in the topology table display a P, the network is stable and is not undergoing recomputation.
The letters R and r are not displayed at the beginning of routes in the topology table. The letter R is displayed after the IP address of a neighbor router that has responded to a query. If a neighbor router has not yet responded to the query, the letter r is displayed after the neighbor's IP address.