Our company presently uses a small Windows 2003 server as a VPN server to allow remote users to connect to our network and open a remote desktop connection to access all apps and resources. I have configured a Windows 2008 Server Standard as a Remote Desktop Gateway server to replace the VPN server, but I am having difficulty connecting to it from a remote computer. We have a CISCO ASA 5500 firewall between our corporate network and the internet.
Can someone please tell me what ports, if any, have to be open and mapped in the firewall from the external IP to the internal IP of the server? Also, can the server be on the internal network or does it have to be on a parallel network? Lastly, we configure the remote computers to access the VPN using Windows basic VPN connections, pointing to the external IP address used in the firewall rule mappings. Do we use the same method to connect to the RD Gateway Server or is it over the internet using https?