We have a persistent tunnel setup between 2 offices.
It has been working perfectly for several months.
Last week, a new issue arose: office A can see resources in office B, but not vice versa.
We've restarted the VPN bridge, and it came back fine.
Office A's logs are showing that office B is attempting to access resources, and it sends them back, but once they reach office B, they are dropped.
We think that Cisco SA520W is dropping the packets. After attempting to access a VPN resource, the router becomes unresponsive - you can't even login. After about 10 minutes it wakes up again.
Firmware is up to date. 2.1.19.
Memory utilization is very high: mid 80s.
What could be issue?