This is driving me batty. I have a Windows SBS2003 machine to which I can connect via RDP as long as I'm on the LAN. I cannot, however, connect over the WAN. I've set up NAT on the Linksys router that sits between the LAN and WAN to direct inbound traffic on port 3389 to the server's IP. I've confirmed that the server is responding to RDP requests on port 3389. The server has a single NIC, so RRAS shouldn't play in to this. The only thing I can figure is that somewhere there's a setting I'm missing where one can define "Grant access for all IPs except the following" or "Deny access for all IPs except the following" (much like you'd set in the security settings for IIS sites).
Can anyone help shed some light on this?