> > I set up my first IPtables box, doing NAT and port > forwarding. I've managed to Google most of the kinks out, but > this one perplexes me. There is a Win2K VPN server behind the > firewall, using PPTP. It will accept connections, but chokes > before accepting the username/password. The most I've been > able to figure out is that it has something to do with protocol 47. > > All other forwards (HTTP, HTTPS, POP, SMTP, Telnet) work > fine. Any ideas? I tried to do exactly what yoru doing, I'll explain where I am. In order to support pptp traffic you have to support protocol 47, and allow traffic forwarding on tcp port 1723. seems simple enough ..... Err no trick is netfilter doesn't nativly support pptp traffic. The two options you have are to get the latest POM and apply the pptp Nat patches. There is also another patch available below. Let me know if yo uget it to work. I gave up and went with an IPSEC implimentation which is just as much a pain in the ass http://www.impsec.org/linux/masquerade/ip_masq_vpn.html
