I am running Debian Etch. It is a new PC, with a Gigabyte mainboard and builtin Ethernet. The Ethernet is:
Whenever I reboot the system (necessary from time to time, for kernel upgrades and power failures), the ethernet device changes (eg was eth0, then eth1 then eth2, etc). More interestingly, the MAC address changes.

The problem is this - this is a server, so a fixed IP address is obviously essential. I use a setting in my ADSL router to assign the same IP address to a MAC address, which works well on all my other systems (where the MAC address is constant, like it should be). I also can't manually set an IP address in /etc/network/interfaces, since the ethernet device changes each time.

I am currently running a Backport 2.6.21-1-amd64 kernel, but the problem was the same with the default Etch 2.6.18 kernel.

Does anyone have any ideas?

Thanks in advance
--Ian

I seem to remember reading about something like this on the Debian User mailing list having to do with that damn udev screwing up the interface like that, don't really have the solution for the problem as I don't use udev but it could be worth searching the archives of debian-user at http://lists.debian.org.

I had to write a udev rule to force mine to be consistantly named. my eth0 and 1 were switching and sometimes being named eth1 ant eth2 on occasion.