EIRGP Hellos queueing and not sending on GRE Tunnel - Page 2

Paul Morgan · ‎06-30-2011

I have just installed a new 887 in a branch office. Two GRE tunnels are configured back to our two head office routers. Only one of the tunnels is able to send EIGRP hellos successfully and hence, one tunnel adjacency is flapping after the RTO is maxed.

Ive tried a few things but Im totally at a loss now.

I can see from debug eigrp packets that the hello is enqueued and that Hellos are received from the tunnel endpoint, but the ACK is generated and queued also. There are no access lists or nat enabled on the tunnel interface and no outbound acls in place. General NAT/PAT is set for the Dialer int.

Ive removed all crypto and any QOS although I dont think these would affect this anyway.

Bear in mind that both tunnels originate at the Dialer and one is working fine.

The SH ip eigrp neigh is shown here

EIGRP-IPv4 Neighbors for AS(****)

H Address Interface Hold Uptime SRTT RTO Q Seq

(sec) (ms) Cnt Num

1 172.20.80.1 Tu0 10 00:00:13 83 5000 1 1784719

0 172.21.80.1 Tu1 13 2d21h 79 474 0 1437249

Any thoughts for tshooting would be greatly appreciated.

At this point Im starting to think it could be an ISP issue?

Giuseppe Larosa · ‎07-06-2011

Hello Paul,

I'm afraid this might be a new bug in 15..1 as the behaviour is strange, or it might need an additional command to fix it.

Hope to help

Giuseppe

Paul Morgan · ‎07-07-2011

So far the distribute list blocking seems to be holding things up.

Thanks for all the help folks.

Giuseppe Larosa · ‎07-07-2011

Hello Paul,

so now you have two EIGRP stable adjacencies one per tunnel?

I consider the suggested distribute lists a workaround

Good to know it worked

This has been an interesting thread with several contributes.

Best Regards

Giuseppe

Paul Morgan · ‎07-08-2011

Yes - two stable adjacencies thanks. And finally a stable routing table!