I can try to find more, but I think this is one (it's in the 3.3 section of the link below):
Aka: We need the changes to persist reboots.
To do so, you need some sh-style script and put this in the appropriate system boot-up directory: /etc/init.d/
Secondly, you create the link in your runlevel directory. The correct directory depends on your gusto
and of course on your linux distribution. Common runlevel values on workstations are 2, 3 and 5. Examples are: /etc/rc?.d/ (replace the ? with the right runlevel)
Also, you need an idea as when your network interfaces are torn up. For now, we assume, your network interfaces are activated at system priority S so we need not to care of. If you ever should feel the need to know exactly, look in /etc/rcS.d/. We just want the bridge to be up and operable as soon as possible and so chose our priority to be 10. (Make sure, no service requiring bridging devices is started before, read: with priority-values less than 10)
For now, we assume, your runlevel is 5:http://tldp.org/HOWTO/Ethernet-Bridge-netfilt...