I'm picking up the following message on one of my VPN routers.
Oct 9 11:31:58.680: %DUAL-5-NBRCHANGE: IP-EIGRP(0) 1: Neighbor 172.31.99.5 (Tunnel1) is down: Interface Goodbye received
I don't understand why EIGRP is clearing the neighbor relations of the GRE tunnel interface.
Cisco states that the message is sent to inform the router of an impending topology change. Peers synchronize and recalculate neighbor relationships more efficiently than would occur if the peers discovered the topology change after the hold timer expired.
Is this feature of EIGRP used to tidy up the EIGRP AS as a whole?