I have a RB532 2.9.50 running PPTP server. When I connect via a XP pc that is ‘straight’ on the network, the connection works, but when trying to connect from behind a NAT router, the connection connects, but windows show ‘disconnected’.
According to Microsoft there was an update in SP2 that enabled XP to do it from behind NAT, but it just wouldn’t work. Well, it works kind of, but you cannot disconnect, XP just shows ‘disconnected’. No firewall rules, pptp & gre services enabled. XP firewall disabled/enabled, doesn’t matter.
When a PPTP client is behind a NAT, a PPTP NAT editor is typically used. A NAT editor is an additional software component on the NAT that performs translation services beyond IP addresses, TCP ports, and UDP ports. Although it is a simple matter for the PPTP NAT editor to monitor incoming packets for GRE payloads and translate the IP addresses in the IP header, there might be multiple PPTP clients behind the NAT. In this case, the NAT is unable to determine to which private client the incoming PPTP data packet is destined, because the same public address is being used for multiple private clients. To determine the private client to which an incoming packet is destined, the PPTP NAT editor uses the Call ID field in the GRE header. However, when two different PPTP clients use the same Call ID, the NAT is unable to determine to which private client the packet is destined.
How can I check if this is working ok on my MT ROS NAT?
Ekkas