Thus spake "Mark J. Scheller" <scheller@u1.net>
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. ... 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.
In my experience, this is most often caused by overzealous NMS types "accidentally" downloading the routing table every few minutes. DoS attacks against routers are thankfully pretty rare, but it's possible. Since you didn't list the IOS version you're running, I can't comment on the odds of this being a bug. S Stephen Sprunk "God does not play dice." --Albert Einstein CCIE #3723 "God is an inveterate gambler, and He throws the K5SSS dice at every possible opportunity." --Stephen Hawking