We have a 3900 (FW v1.4.2.1) configured with an IPSEC tunnel to a Cisco ASA 5550.

In terms of the tunnel stability, it all appears to be rock solid with no unexpected dropping of the tunnel.

However, in terms of traffic things are a little different with the sudden inability to pass traffic down the tunnel.

This occurs at total random times and doesn't appear to be triggered by anything that I can put a finger on.

Checking the status of the tunnel on the 3900 shows the tunnel up, however pinging a device at the other end fails.

Restarting the tunnel will get the traffic flowing again.

Couple of questions:-

1. Anyone else experiencing the same issues?
2. Any tips on how to pin down where/what the issue may be?

Thanks in advanced.

We've seen a similar issue: we've noticed that the routing table drops the route but the VPN stays up. Can't recall if it was a Cisco at the other end of the connection because it's another company hosting that equipment.