Has anyone experienced a problem with dropped individual IPsec sessions within a lan-2-lan connection if you are using network lists which necessitate several different IPsec session within the connection? For instance say your have a LAN-to-LAN connection with three subnets defined for one side of the tunnel and 12 subnets on the other side of the tunnel. This would result in having one IKE session for the and several different IPsec sessions each with its own session ID. What we are finding is that after running okay for days or weeks - one of those IPsec sessions might disappear and traffic between the affected subnets won't pass. I'm speaking of a PIX to a CVPN3000.
It seems like the problem does not crop up when you have a very simple setup like a spoke office with one subnet which tunnels a few subnets to a CVPN.
