I have been using "debug ip packet" on a Cisco 2921 running IOS 15.1(4)M1. The problem I have is that, although I am using an ACL to limit the output, I am seeing some output that is distracting from what I am trying to see. Specifically, I am seeing the following:
Mar 19 20:22:36.135: IP: s=192.168.20.253, d=184.108.40.206, pak 30DB6D4C consumed in input feature , packet consumed, MCI Check(80), rtype 0, forus FALSE, sendself FALSE, mtu 0, fwdchk FALSE
Mar 19 20:22:38.951: IP: s=192.168.20.253, d=220.127.116.11, pak 2A74FFE8 consumed in input feature , packet consumed, MCI Check(80), rtype 0, forus FALSE, sendself FALSE, mtu 0, fwdchk FALSE
These would appear to be HSRP messages. But I don't understand why they are appearing when I configure "debug ip packet 101". The ACL is pretty simple:
access-list 101 permit icmp host 18.104.22.168 host 192.168.20.1
access-list 101 permit icmp host 192.168.20.1 host 22.214.171.124
So I thought the implicit "deny ip any any" would block these messages. I even tried to block them specifically using an extra line:
access-list 101 deny udp host 192.168.20.253 host 126.96.36.199 eq 1985
But still they show up! Any ideas?
The router seems to be hitting the bug CSCtx12810:
I would let you know the IOS versions which would contain a fix for this bug.