http://openvpn.net/index.php/open-sourc ... dging.html
I guess this is what happens to most of the users who wanted to bridge..A common mistake that people make when manually configuring an Ethernet bridge is that they add their primary ethernet adapter to the bridge before they have set the IP and netmask of the bridge interface. The result is that the primary ethernet interface "loses" its settings, but the equivalent bridge interface settings have not yet been defined, so the net effect is a loss of connectivity on the ethernet interface.
- gabbo