Show IP EIGRP Neighbor
This command shows EIGRP adjacency information on the router. This information includes neighbor IP address and the interface that the neighbor is connected to. This also shows the queue (Q). If the queue is ever above zero there is a problem with your network and EIGRP routers will be inactive.
Router#show ip eigrp neighbor
In the below example we see the EIGRP neighbor information on R2
R2(config)#do show ip eigrp neighbor IP-EIGRP neighbors for process 100 H Address Interface Hold Uptime SRTT RTO Q Seq (sec) (ms) Cnt Num 0 10.1.1.1 Fa0/0 11 00:12:00 168 1008 0 69 1 10.2.2.3 Fa1/0 11 02:32:19 82 492 0 61