I have a Safe@Office 500P appliance and have a site-to-site VPNs to connect to our production and contingency sites. Production is running Check Point R75.20 on IP390 Cluster and the contingnecy platform is running Check Point NGX R65 HFA70 with Hotfix on IP380 Cluster.

The site-to-site VPN's have been working fine since I upgrade the Safe@Office appliance to 8.2.50x last Monday however now cannot ping one subnet on our production platform for a period of time and then it will eventually come back with no intervention on my part. I have had to put a NAT rule in on both platforms that says anything going to the Safe@Office network leave the source IP address as the original to get the servers on the production and contingency platform to work in order for the servers on both platforms to ping servers behind the Safe@Office appliance.

Once I can ping the networks it sometimes lasts for 5 mins or for an hour.

What could be causing this issue?