• Software
• OpenVPN in VServer

Work in progress

http://linux-vserver.org/Frequently_Asked_Questions#Can_I_run_an_OpenVPN_Server_in_a_guest.3F
http://debianforum.de/forum/viewtopic.php?f=30&t=127504

http://www.techrepublic.com/blog/opensource/how-to-set-up-an-openvpn-server/1873
http://openvpn.net/index.php/open-source/documentation/howto.html#install

http://wiki.cacert.org/openVPN
http://robert.penz.name/21/ovpncncheck-an-openvpn-tls-verify-script/
http://wiki.yobi.be/wiki/Virtual_Private_Networks

http://openvpn.net/index.php/open-source/documentation/manuals/65-openvpn-20x-manpage.html
        ifconfig-pool-persist
        persist-tun

# Downgrade to an unpriviledged user for security after initialization
user nobody
group nobody

# Use a persistent key and tunnel interface. Helpful if running as an
# unpriviledged user and the connection goes down.
persist-key
persist-tun