I have a network with a static IP that has an Avaya SG200 router. I need to establish a VPN connection to my Windows 2003 SBS on the private side of the avaya. I've "redirected" port 1723 to the private IP of the server and opened the GRE 47 service with still no luck. After it connects, it says verifying user name and password then times out "error 721".
Inside the network, my server accepts the VPN connection with ease.