Is there a problem masquerading PPTP traffic in the pre-built 2.2.16-22 kernel supplied with RedHat 7.0? I have successfully set up to masquerade other traffic (HTTP and FTP), but the PPTP masquerading (of a win2000 PPTP client) does not seem to work. If I dial my ISP directly from the PPTP client machine then the PPTP stuff all works a treat. When I try and connect through my firewall (RedHat Linux 7.0) then it attempts to connect but fails. I seem to be able to telnet through my firewall to port 1723 of the PPTP server, and using tcpdump I can see lots of stuff allegedly going through the firewall.
I think there is a problem. I had pptp masquerading working fine under patched 6.2, but after upgrading to 7.0, all other things remaining the same, pptp masquerading via the RH7 default ip_masq_pptp module doesn't work.
http://www.impsec.org/linux/masquerade/ip_masq_vpn.html states you need this patch: ftp://ftp.rubyriver.com/pub/jhardin/masquerade/ip_masq_vpn-RH2.16-2.patch.gz on 7.0. Unfortunately I have been unable to recompile the kernel after applying this patch, but that could be unrelated!
Thanks for the bug report. However, Red Hat no longer maintains this version of the product. Please upgrade to the latest version and open a new bug if the problem persists. The Fedora Legacy project (http://fedoralegacy.org/) maintains some older releases, and if you believe this bug is interesting to them, please report the problem in the bug tracker at: http://bugzilla.fedora.us/