I have a few SG560 firewalls as well as a couple of Linksys RV082 routers and a couple of WatchGuard x550e firewalls.
For some reason, after upgrading to the firmware v3.1.6 the SG560's frequently become inaccessible with via HTTP or SSH and require restarts. Just as frequently they will drop VPN (IPsec) tunnels which require resetting the VPN. I do not have these issues at all with any of the other brands.
Can anyone help shed some light on this issue for me.
PS. I tried upgrading to the 4.x firmware versions but the devices seem to completely choke up as soon as the VPN tunnels connect so I set them all back to the v3.1.6.