Comment 2 for bug 49121

I guess the user is supposed to telepathically know what iftab is? /etc/iftab is part of the ifrename package, which is not part of the stock *buntu installation. Just install ifrename, then follow the above example. Works like a charm.

You cannot predict what order the kernel will bring up interfaces in, this is typical of any Linux, though usually it is consistent until you upgrade or make some other change.