I am trying to create a startup script for backtrack that will alter my IP and MAC address on startup. I found several tutorials on how to write an init script, but I can't seem to find one that explains how to use /dev/random (random # generator) alongside the MAC and IP change commands.

Can I do this with /dev/random? Or is there a better function that is built into Ubuntu or the linux kernel?

How would I go about doing this? Also, can I implement this BEFORE the networking services run? Or do I need to wait until after then do the normal start/stop commands?