7.34. ( VPNs ) - I would like to get Microsoft PPTP (GRE tunnels) and/or IPSEC (Linux SWAN) tunnels running through IP MASQ

This IS possible for specific modes. Specifically, all of the kernel versions (2.4.x, 2.2.x, and 2.0.x) support patches to allow for both ONE or MULTIPLE PPTP users behind a IPMASQ server to connect to the -same- PPTP server. The 2.4.x kernels currently have a PPTP module now in the newest versions of the IPTABLES program and there is another version available on the IPMASQ WWW site. Please check out John Hardin's PPTP Masq page for details.