I had a perfectly working router-to-router VPN using IOS 12.2(17) on both routers. I upgraded one of the routers to 12.3(9), but made absolutely no changes to the config. Both IOS versions have the same feature set (crypto). Now the routers will not establish the ISAKMP security assocation. Anyone have any suggestions? Upgrading the 12.2 router to version 12.3 is not an option at this time. Thanks.
