I am trying to get a Window2000 Server VPN (PPTP) server behind my linux firewall to work. I have been able to forward web trafic to the internal server just for testing.
I currently have this for NAT... iptables -t nat -A POSTROUTING -s 172.20.40.0/24 -o eth0 -j MASQUERADE And this for the forwarding of traffic on port 1723 (PPTP)... iptables -t nat -A PREROUTING -p tcp --dport 1723 -i eth0 -j DNAT --to 172.20.40.2 I know that PPTP uses GRE (protocol 47) after the connection is made. The connection is initiated with a tcp connection to port 1723. When I initiate a connection from a VPN PPTP client it gets as far as authentication. It finds the server and the server responds asking for authentication information. After that it dies. eth0 - 68.3.233.69 (internet connection) eth1 - 172.20.40.1 (lan connection) ip of internal PPTP server - 172.20.40.2 Any help would be great. Let me know if more information is needed. Thanks, Carl
