sh ip eigrp neighbors

R2#show ip eigrp neighboursIP-EIGRP neighbours for process 1 H     ADDRESS             INTERFACE        HOLD      UPTIME      SRTT    RTO     Q        SEQ       TYPE 1      172.16.3.4          S0/0/0                  10           00:01:41    20        200      0          7 0     192.168.56.85   S0/0/1                  10           00.09.49    25         200      0          28

The output from the show ip eigrp neighbor command includes:

H column – Lists the neighbors in the order they were learned.
Address – The IP address of the neighbor.
Interface – The local interface on which this Hello packet was received.
Hold – The current hold time. Whenever a Hello packet is received, this value is reset to the maximum hold time for that interface and then counts down to zero. If zero is reached, the neighbor is considered “down”.
Uptime – Amount of time since this neighbor was added to the neighbor table.
SRTT (Smooth Round Trip Timer) and RTO (Retransmit Interval) – Used by RTP to manage reliable EIGRP packets.
Queue Count – Should always be zero. If more than zero, then EIGRP packets are waiting to be sent.
Sequence Number – Used to track updates, queries, and reply packets.

If a neighbor is not listed after adjacencies have been established, check sh ip int br to make sure the interface is active and if a ping is successful but EIGRP still does not see the router as a neighbor, examine the following configurations:

• Are both routers configured with the same EIGRP process ID?

• Is the directly connected network included in the EIGRP network statements?

• Is the passive-interface command configured to prevent EIGRP Hello packets on the interface?