Router too busy???

Tue Apr 1 19:06:00 UTC 2003

This last Saturday (29 Mar 2003), about 4pm Eastern time my router -- for lack
of a better term -- wigged out.  I was able to ping to & through it, however
any attempt to get a TCP connection (specifically ssh and http) was almost
immediately terminated.  I think DNS was working fine, which would hint that
UDP was getting through as well, but I won't swear to that in court.

After convincing someone to drive to its location and do a power cycle, it
rebooted happily and has run fine since.  My mrtg graphs show that the CPU was
pegged at 100% during the time it was acting up; memory was fine; traffic was
(not surprisingly) very low -- and no spike prior to the CPU getting pegged.

I've been running this version of IOS since it was released as a response to
the flaw found in SNMP.... and the router has been rock solid!  CPU is
normally 15-20% with occasional spikes, but never for long.  Memory erodes
slowly, but never dropping below 20MB.

Has anyone seen anything like this before?  Basically, I'm wondering whether
this may be an IOS bug or whether I may have hardware on its way out or
whether this was some kind of new crafty DoS attack.

TIA!

Mark J. Scheller (scheller at u1.net)