OpenBSD: How To Create a Transparent Bridge

A network bridge is a device which connects two parts of a network together. In this article I'll show you how to create a transparent bridge in OpenBSD.

To activate the bridge in OpenBSD run the following commands:

echo up > /etc/hostname.xl0
echo up > /etc/hostname.xl1
echo add xl0 add xl1 up > /etc/bridgename.bridge0

This will setup the two interfaces (xl0 and xl1) and add them into the bridge0.

Now, you need to enable IP forwarding so that IP packets will pass from one interface to another.
To enable ip forwarding add the following line to /etc/sysctl.conf:

 net.inet.ip.forwarding=1

Once this is all done, reboot to activate.

reboot