This is the Linux VPN howto, a collection of information on how to set up a Virtual Protected Network in Linux (and other unices in general).
This document is part of the Linux Documentation Project. The copyright notice is the following:
The VPN mini HOWTO written by me can be copied, distributed, and/or modified under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with the Invariant Section being the section entitled "About the ppp over ssh vpn technique", with any Front-Cover Text containing the p= hrase "Based on the work of Arpad Magosanyi", and with any Back-Cover Text.
As usual: the author not responsible for any damage. For the correct wording, see the relevant part of the GNU GPL 0.1.1
We are dealing with security: you are not safe if you haven't got good security policy, and other rather boring things.
Thanks to all of who has written the tools used.
Thanks to Zot O'Connor <firstname.lastname@example.org> for pointing out the "no controlling tty" problem, and it's solution.
This is very preliminary. You should have thorough knowledge of administrating IP, at least some knowledge of firewalls, ppp and ssh. You should know them anyway if you want to set up a VPN. I just decided to write down my experiences not to forget them. There are possibly some security holes indeed. To be fair I've tried it on hosts configured as routers not firewalls, saying: It's simple from that point.