I'm fighting a Zywall USG 100 firewall that will not connect Remote Desktop from a remote computer to a computer on the domain behind the firewall. I can't ping the firewall from outside of the LAN, but I can ping out OK. I can open an IPSec VPN tunnel with ZyXel IPSec VPN Remote Client but nothing happens. I have tried using networks with different network schemas. I created an object/address, NAT & firewall rule. I created an RPD service for port 3389, but then found that the USG 100 has a remotelogin on port 513. I don't know if that has a different purpose. I haven't been able to get a complete set of instructions, so I can't be positive that all the settings are correct. The user manual is not completely clear about configuration for a static domain network with a dynamic remote client. I've been losing time on this for 2 weeks & it has to be finished. Any help is appreciated.