I have five (5) RVS4000's setup at five (5) different locations with site-to-site VPN configured between them all. I am using "IP by DNS Resolved" for the remote group with dyndns.org as my dynamic DNS service. All routers are running the 220.127.116.11 firmware.
My issue is that VPN tunnels seem to go down every so often. Sometimes I can go weeks without it going down. Sometimes it is within days of a reboot.
Sometimes simply hitting the respective "Connect" button on the VPN summary (or IPSec VPN Details) page for the local router re-establishes the connection and sometimes it does not. Sometimes I have to access the remote admin UI (https://xxxxx:8080/) to hit the respective "Connect" button to re-establish the connection, which sometimes works and sometimes does not work. And other times I have to reboot at least one of the routers to get the connection to re-establish.
This type of behavior does not seem correct. Is anyone else seeing this behavior? Are there any strategies I can use to diagnose the issue?