Core Issue
Enhanced Interior Gateway Routing Protocol (EIGRP) builds a topology table with metrics of feasible distance and reported distance for each route. To see the table, issue the ip eigrp topology command.
All the routes with a feasible distance greater than the reported distance are not installed into the IP routing table. Among the routes in the EIGRP topology table, the route to a particular destination with the smallest metric is installed into the routing table.
For more information, refer to the Feasible Distance, Reported Distance, and Feasible Successor section of Enhanced Interior Gateway Routing Protocol.
Resolution
To resolve this issue, determine if the prefix exists in the EIGRP topology table by issuing the show ip eigrp topology [prefix mask] command.
The prefix with the smallest metric should be installed into the IP routing table. If the prefix does not exist in the EIGRP table, resolve the EIGRP neighbor towards the source of the route.
For more information, refer to Troubleshooting EIGRP.