Hallo, I was using a self-compiled kernel 2.6.21, with eth0 and eth1 under FC6. After reboot with the identically configured kernel 2.6.21.5 the two interfaces got switched, eth0 was eth1 and eth1 was eth0. And my "/etc/modprobe.conf" contains alias eth0 natsemi alias eth1 8139too What's going on? And how to prevent this? --Frank Elsner