I try several configuration to make a "correct" Site-to-site VPN between a RV082 (Firmware 126.96.36.199) and a Cisco 2811 (firmware advsecurity 12.4(15)T9 - using SDM interface)
A each time the VPN work correctly.... during few minutes and after it was impossible to ping (for example) anything... But the VPN statuts still connected !!!
When the "tunnel breack" :
From the RV082 LAN : I can't do nothing (no ping, and anything else) and when I try a traceroute, it take a wrong way (hope to the internet instead of vpn...). Of course I can't ping the 2811 Lan interface...
From the 2811 LAN : I can only ping the RV082 Lan interface (192.168.0.1) and can't ping any other LAN machine
BUT I still access to them (Web interface, Display remote (like VSM or Dameware) !!! it's very strange !
If I restart the VPN (from the RV082) all return good... during 3-4 minutes...