OpenVPN is a Free VirtualPrivateNetwork daemon that uses SSL.

OpenVPN bridging with a Windows RoadWarrior

Is this information at all Windows-specific? --AristotlePagaltzis

Set up your Kernel for briding (bridging?) and tun/tap devices.

First, create /dev/net/tun.

mkdir /dev/net
mknod /dev/net/tun c 10 200

Then, configure /etc/network/interfaces to bring up tap0/tap1/br0:

auto tap0
iface tap0 inet static
address 0.0.0.0
netmask 255.255.255.0
network 192.168.1.0
broadcast 192.168.1.255
pre-up /usr/local/sbin/openvpn --mktun --dev tap0

auto tap1
iface tap1 inet static
address 0.0.0.0
netmask 255.255.255.0
network 192.168.1.10
broadcast 192.168.1.255
pre-up /usr/local/sbin/openvpn --mktun --dev tap1

auto br0
iface br0 inet static
address 192.168.1.x
network 192.168.1.0
netmask 255.255.255.0
broadcast 192.168.1.255
bridge_ports tap0 tap1 eth0

See also:

• Ethernet Bridging Mini-HOWTO
• OpenVPN Win32 Install
• FedoraNEWS.ORG: Implementing OpenVPN
• OpenVPN 2.0 beta series release notes