Hello everyone, I've come across a strange issue with a VPN running between 2 2600 routers. This affects only one of the two routers.
Basically, there is an intermittant failure of ISKMP negotiation. An ACL is filtering the 'outside' interface, though with all required ISAKMP/IPSec traffic etc. allowed. However, if I remove the ACL when the ISAKMP is failing everything starts to work. I wondered if anyone else had seen someting like this or know its likely cause?