hi folks,
I,ve written a script to make live easier with tun/tap devices and bridges.
it has been my first bigger project, so don't expect a perfect one, but it works.
http://vosp.info/index.php/VirtualBox#bridgebuild_0.2
with it, you can keep track of the bridges and the attached devices, adding, deleting etc.
to find out what it can do, take a look at case *). it contains the "help" section.
the best is to create all the bridges and tap devices you need, put them into the virtual-box control panel and start the machines.
heiko