[c-nsp] Mac address flapping..

[Phil Mayers]

On Sun, Jul 12, 2009 at 06:09:05AM +0100, James Ashton wrote:
>I have looked at all the port configs in question.    No forgotten stuff that I can see.
>
>I am willing to go with the loop idea..  But I dont get any loop errors.   I dont get any Mac Move errors other than for this HSRP Mac Address, and over 120 other vlans on  these same ports arent having this issue.
>
>
>But if it were a loop, how would I find it and fix it..   I ahve gone through every method I know of and allt he Cisco troubleshooting docs.   I can feel that I am missing something here, But I just cant think of what.
>

Next step is to SPAN the ports concerned and confirm "for real" what 
packets are causing the mac move notify, and see what else is there that 
shouldn't be

It's possible the loop isn't a "full" one; e.g. if they've looped subnet 
200 to 201, via a firewall that's dropping non-IP packets, then STP 
wouldn't complain, and you wouldn't get a broadcast storm, but you would 
get this kind of problem.