Hi. I'm new in this forum as post-man ;-), but I am a read-post-man for a long. Now I have a problem in a new installation. I have a RV082 configured as VPN endpoint in a central office. This is conected to internet trought a ADLS router; the NAT in this ADSL router is sending port 500 to the RV082. i have about 8 BEFSX41 routers in branch offices conecteds to internet in a similar way, via ADSL routers with NAT on port 500. FW are 18.104.22.168 for RV082 and 1.52.10 for the BEFSX41. I have configured IPSEC VPN from every branch BEFSX41 to the central RV082. The config that I've used is: dinamic ip with email autentication, and agresive mode (in the BEFSRX41) with the email put as the username. I have selected PFC (Perfect Forward Secrecy), keep Alive, and I use DES, SHA, 768 Bits, y Key Lifetime 3600 sec. Tunnels are running correctly EXCEPT that sometimes, ip comunication trought the tunnel is lost. The tunnel remains active, but I can't establish a telnet connection to the other side. If I "Disconnect" the tunnel and reconect again, telnet pass the tunnel without problem for another time. I have one branch that are more robust. This router is running from 5 days without lost communication. I have a telnet session opened with a script that request the time every 30 seconds. i don't know if this is important to let the tunnels stables (put some traffic in the tunnel). Any Ideas?