Our ISP has issued our D-link DI-604 Router a WAN IP of 192.168.xxx.xxx, due to the fact we are behind thier firewall, however, they have also given us a public IP. Their firewall which port forwards the WAN IP to our Router (LAN IP 192.168.xxx.xxx) which port forwards to our Server... The ISP is telling me that they have to open all ports of their firewall to allow RDP to happen? They are asking me the following....
"Remote Desktop started working when i opened up all ports on our firewall. Remote
Desktop needs more than 3389 to work correctly which is why I wanted you
to remove all rules except one in the router for debugging.
Please send me the ports it needs so i can open up just those ports."
From my understanding RDP using only port 3389 to 3389? Are all ports required to be opened on our ISP's Firewall to allow RDP to go through? Without all ports opened up from our ISP, the RDP does not work?