Weird one with a 2801 connected directly to an ASA-5510?

[ADB100]

I was at a site over the last few days where there is a 2801 that is directly connected to an ASA-5510 Firewall (it's actually FastEtherent0/0 on the 2801 connected to Ethernet0/2 on the ASA). The ports are set to Auto speed & duplex and have negotiated 100/Full (I have tried hard-coding as well which has the same behaviour). Every 30-seconds the 2801 reports a link up message:

003868: Nov 25 23:26:07.929 GMT: %LINK-3-UPDOWN: Interface FastEthernet0/0, changed state to up 
003869: Nov 25 23:26:37.926 GMT: %LINK-3-UPDOWN: Interface FastEthernet0/0, changed state to up

This is constant and doesn't change whether the interfaces are hard-coded 100/Full or left at auto. I thought it might be a CDP weirdo so I disabled CDP on the 2801 FE0/0 interface but the behaviour is the same. Previously the connection was via a Catalyst 3560 and the message was never displayed then, however due to the security requirements the 2801 has to be connected directly to the ASA.
There are no errors on either interface and the connection seems to be working fine. There are IP Phones using the 2801 as a gateway and calls are unaffected. It looks like a cosmetic issue but is slightly worrying.
Has anyone seen any similar behaviour or has a solution/workaround?

Andy

 

[burtsbees]

Forgive me, but I must ask...have you eliminated ALL layer one, I.E. cable, different interfaces in the ASA and/or router, etc? Was the 3560 plugged into the same ASA port, eliminating (almost) the ASA as the problem? No link down messages? Reboot the router lately?

Burt

 

[ADB100]

Forgive me, but I must ask...have you eliminated ALL layer one

Yes. I have replaced all the cables. I can't actually see any errors being logged on either the 2801 or the ASA, thats why it's so weird. Everything appears to be working fine except for the messages - if the interface was transitioning then we would have IP Phone issues. I made an external call from an IP phone that uses the 2801 as a gateway and left it open. I then opened the stats page on the phone and it was perfect (1 discard...). That is why I think it is something cosmetic or maybe some low-level signal that the 2801 is receiving and results in the message.

I think it's probably going to have to be a TAC case......

Andy

 

[burtsbees]

Yes, I would vote out a flapping interface. I am sure you had tried all L1, but just wanted to maybe jog your brain to see maybe "oh yeah, forgot that one", so again, I apologize. Exactly every thirty seconds though? Have you looked this up in the Bug Toolkit, for maybe an IOS bug?

Burt