1. Have you checked the health of the serial interfaces? (line hits, CRC errors, dropped packets, etc) 2. Did the traffic over the line increase dramatically? 3. Although it sounds like these are production routers, have you looked at a short-timed trace of 'debug crypto ipsec' and/or 'debug ip isakmp'? Do your 'show crypto' stats show anything revealing? -e- ----- Original Message ----- From: Gareth Hinton To: Sent: Tuesday, June 19, 2001 6:29 PM Subject: Strange Encryption Problem/Mystery/Bug???? [7:9131] > Hi all, > > Thought I'd ask if anyone has experienced similar to a problem I've had > recently. It's going to TAC now and I've got a workaround, but I'd be > interested if anyone could suggest the reason or confirm a bug which I have > been unable to locate. > > These routers had been running for nearly a year with no problems. All of a > sudden they started giving problems and I have been unable to track down > what external network changes may have triggered it. There were no config > changes to the two routers (We run Resource Manager Essentials which > monitors router config changes) > > Set-up was two 3660's running 12.1.1T, DES encryption over serial 2Mb link. > The links were set up with encryption peers as the serial IP addresses and > encryption access lists set up symmetrically without using any any on the > serial interfaces. > > After reload routers come up fine and encryption runs O.K. > After a varying length of time (around 5-10 minutes), the CPU utilisation > builds up gradually until it sits at around 98%. This utilisation was almost > totally due to encryption process. > > After swapping out the router and upgrading IOS, the problem still existed. > > I have got around the problem by using IP Unnumbered Loopback0 on Serial > links. CPU utilisation now hovers around 2%. > > Anybody seen similar, or suggest what could make the CPU utilisation > snowball like this? > > > Thanks, > > Gareth Hinton Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=9145&t=9131 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
