PPTP through masquerading gateway

[Marc Riddle]

I have read everything I can find on the subject and can't seem to find a working solution anywhere. I have an NT 4.0 server running a PPTP server inside a private network that is connected to the internet via a linux 2.4 box running ip masquerading using iptables. the masquerading works fine for clients to get out, but I'm trying to enable external connections in to the PPTP server. currently I have the following rules set up, as far as I can tell they should work, but I am unable to establish a connection. The PPTP server is running on 10.1.1.15, and I am able to connect to it from inside the router so I know that it is running fine. I've been banging my head against a desk for about a week now and nothing I've tried seems to work. Any advice would be greatly appreciated. Thanks in advance. Oh yeah, currently the rules below are the only rules set up for testing, so no incoming packets are being filtered that I know of.   Thanks again,   Marc Riddle iptables -t nat -A POSTROUTING -o ppp0 -j MASQUERADE iptables -t nat -A PREROUTING -i ppp0 -p tcp --dport 1723 -j DNAT --to 10.1.1.15 iptables -t nat -A PREROUTING -i ppp0 -p 47 -j DNAT --to 10.1.1.15