Today I upgraded our host server to XenServer 6.0 and upgraded the SBS 2008 VM with the latest XenTools. Everything has gone fine.
When I connect to the SBS server over VPN, it connects fine. From my local PC over the VPN, I can ping SBS but cannot ping any other PC on the same network as SBS. If I RDP in to the SBS server, I can ping anything on the network.
Does anyone know what else I can try? Really stuck on this one myself. :(
EDIT: When XenServer was upgraded, the virtual network adapter in SBS was replaced and given a new IP, so I've had to setup the SBS local IP settings again. Prior to the upgrade the VPN worked fine. This problem has been occurring since the upgrade only. I've tried removing and reinstalling Routing and Remote Access, followed by a reboot, but it's still not working.