Can't access internal resources

Hi,

I've set up my Untangle Open VPN box in router mode. OpenVPN is the only utility in the rack. I can connect with VPN server from the client externally. I can ping the internal IP of the VPN server and connect to the the admin GUI. However I cannot access any internal resources. I cannot ping the internal servers by IP either. The FQDN don't resolve even though I've exported the DNS.

I've tested the VPN server and it can ping the internal IP addresses from it's console.

Any help would be much appreciated.

Dave