Urgent qestion. 7206VXR locks up for 10 sec at a time, drops BGP!!!

[jasonhumes]

Hi

We've got a 7206VXR with NPE route processor. The problem we are seeing is that sometimes (as often as every 10 minutes, sometimes as long as 8 hours) the router will seem to lock up or stall temporarly, at which point the console stops responding and bgp routes start to exprire and then eventually drop out totally, untill the router comes back around again (which it does on its own after a few minutes, or seconds sometimes). Also, while this is happening, local routing seems to work just fine and the memory and CPU utilization are within normal limits. Any ideas. Thanks

[ruwhite]

It sounds like your TCP stack is being attacked in some way--a fin wait 1 or syn attack, maybe. I would look around for signs of this, or set up access lists blocking all tcp into the box other than from hosts you would telnet from and the bgp peer, and see if that helps, possibly.

:-)

Russ.W

[jasonhumes]

Sorry for the noob question, I know how to deal with this on a pix firewall, but on a router, how do I go about detecting this syn/fin attack and also, how could I mitigate the effects if that is what it turns out to be. I dont think I've got the firewall feature set on that router, which means that IP Inspect is out of the question. Thanks

[glen.grant]

you could turn on ip route cache flow and take a look at the flows and see if there is a pattern or if there is a lot of traffic coming from one source .

[deilert]

what code are you running ? We had a similar problem , all the interfaces would remain up up and not pass any data , the console would also lock up

[jasonhumes]

We are running ver 12.2.19...Any ideas?

[deilert]

no sorry , this was happening to us on 12.0(7) T , we have not had any problems with 12.2(19) .