Running 12.2(15)T17 in a lab environment on a 2520. Half way through my lab exercise, this router suddenly has no EIGRP neighbors. The neighbors still think they have adjacencies. Then they start flapping too - not through dead-time, but because retry exceeded.
Looking back through the log, I find, just following a reload:
Oct 28 17:27:38.197: %OSPFv3-5-ADJCHG: Process 100, Nbr 126.96.36.199 on Serial2 from LOADING to FULL, Loading Done
Oct 28 17:27:38.721: %BGP-5-ADJCHANGE: neighbor 188.8.131.52 Up
<b>Oct 28 17:27:41.981: %SCHED-3-UNEXPECTEDEVENT: Process received unknown event (maj 0, min 0).
-Process= "IP-EIGRP: HELLO", ipl= 0, pid= 93
Oct 28 17:27:45.841: %BGP-5-ADJCHANGE: neighbor 184.108.40.206 Up
Oct 28 17:27:50.093: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 12: Neighbor 220.127.116.11 (Serial2) is down: holding time expired
Oct 28 17:27:50.109: destroy peer: 18.104.22.168
Oct 28 17:27:50.789: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 12: Neighbor 22.214.171.124 (Ethernet0) is down: holding time expired
Oct 28 17:27:50.857: destroy peer: 126.96.36.199
Oct 28 17:27:51.549: %OSPFv3-5-ADJCHG: Process 100, Nbr 188.8.131.52 on OSPF_VL0 from LOADING to FULL, Loading Done
Has anyone any idea what that could be about? At the time, I was not touching anything to do with the EIGRP. The only thing that should have been going on was some IPv6 routes turning up through the OSPFv3.