Paranoid Penguin - Linux VPNs with OpenVPN
OpenVPN is already a standard part of many Linux distributions. Ubuntu, Debian, SUSE and Fedora, for example, each has its own “openvpn” package. To install OpenVPN on your distribution of choice, chances are all you'll need to do is run your distribution's package manager.
If your distribution lacks its own OpenVPN package, however, you can download the latest source code package from www.openvpn.net. This package includes instructions for compiling and installing OpenVPN from source code.
Now that you've got some idea of the uses of VPN, different protocols that can be used to build VPN tunnels, different Linux tools available in this space and some of the merits of OpenVPN, we're ready to roll up our sleeves and get OpenVPN running in both server and client configurations, in either “bridging” or “routing” mode.
But, that will have to wait until next month—I'm out of space for now. I hope I've whetted your appetite. Until next time, be safe!
Mick Bauer's Paranoid Penguin, January 2005, “Linux VPN Technologies”: www.linuxjournal.com/article/7881
Wikipedia's Entry for IPsec: en.wikipedia.org/wiki/IPsec
Home Page for Openswan, an IPsec Implementation for Linux Kernels: en.wikipedia.org/wiki/IPsec
Home Page for Strongswan, Another Linux IPsec Implementation: www.strongswan.org
Home Page for pptp-linux (not recommended): pptpclient.sourceforge.net
Poptop, the PPTP Server for Linux (not recommended): poptop.sourceforge.net/dox
Tools and Papers Related to Moxie Marlinspike's SSL Attacks (and Others): www.thoughtcrime.org/software.html
“Major SSL Flaw Find Prompts Protocol Update”, by Kelly Jackson Higgins, DarkReading: www.darkreading.com/security/vulnerabilities/showArticle.jhtml?articleID=221600523
Official OpenVPN Home Page: www.openvpn.net
Ubuntu Community OpenVPN Page: https://help.ubuntu.com/community/OpenVPN
Charlie Hosner's “SSL VPNs and OpenVPN: A lot of lies and a shred of truth”: www.linux.com/archive/feature/48330
Mick Bauer (email@example.com) is Network Security Architect for one of the US's largest banks. He is the author of the O'Reilly book Linux Server Security, 2nd edition (formerly called Building Secure Servers With Linux), an occasional presenter at information security conferences and composer of the “Network Engineering Polka”.