07 Apr 2011 - Lab-Rat

Here are some notes to remember and commands for debugging EIGRP:

Neighbor Requirements

EIGRP and Frame - Split horizon is ON BY DEFAULT on frame links.

show ip eigrp neighbor
- shows neighbor status. Look for 0 under Q count in good relationship.

debug eigrp packet hello
- sending hellos?

debug ip eigrp
- shows routes blocked by distribute lists

debug ip routing or debug ip routing 1 (for just the target route)
access-list 1 permit
access-list 1 deny any
- shows route being constantly added

show ip eigrp interface
- shows peers, round trip time, pending routes

show interface s0/0/0
- shows the delay and bandwidth set on the interface. Remember to add them for a cumulative route value.

show ip protocol
- will show the K values for EIGRP

- check eigrp listeners

clear ip eigrp neighbors
- Will reset neighbor relationships and kick off DUAL

show ip route x.x.x.x
- Shows the routing table with details on x.x.x.x
show ip route eigrp
- Shows the EIGRP routes in the routing table

show ip eigrp topology x.x.x.x
- Shows the eigrp database

show ip eigrp event
- troubleshooting flopping route. Look for timer update 0:00:00, find neighbor doing update.

show ip eigrp topology active
- hunt stuck in active on each neighbor

debug eigrp packet
- will show authentication failures

Additional Reading:
Troubleshooting EIGRP
EIGRP Commands
Troubleshooting IP Routing Protocols
Also check out general debugging under Debug RIP.