I have a Cisco ASA 5512 that is making a site to site vpn with a client that has a watchguard xtm 26. The tunnel appears to work fine initially. I can see the tunnel come up and traffic is flowing just fine. However, sometime later in the day, the tunnel just stops passing traffic. I can see that the tunnel is up, but data attempting to be sent from client site just doesn't seem to hit my firewall. The only solution we have found so far is be constantly pinging from the client's host to my host. The tunnel has then stayed up with no issues. Any ideas? Let me know if there is any information I can give you to help. Thank you.