Problems with Site-to-Site VPN Tunnels all of a sudden
(I have already opened a case and had it escalated - just looking for input)
I have (4) TZ 600's, (1) TZ 500, (1) TZ350, & (1) TZ300. I have VPN tunnels between all of them. Have worked flawlessly for 3 years. I have changed nothing - for the last 4 nights, I have one TZ600 that is dropping all or most of the tunnels at roughly the same time at night (12:00pm - 1:00am). The internet never drops, just the tunnels. The tunnels will not reconnect until I restart the TZ600. When I restart the TZ600, the tunnels that were down will come back up and the tunnels that were up previously will not come back up - yes, very weird. I then have to wait a period of time to restart again and the remaining tunnels will then come up. First level support has found nothing that is preventing the tunnels from coming back up (nor why they are dropping). Any suggestions are appreciated.