I had a similar problem but not NM related when I added two 1GB nics to a box that had a 100MB onboard nic. I wanted the two 1GB nics to be eth0 and eth1 but the onboard nic would always revert to eth0 on reboot. I could bind them with system-config-network but could not get them to stay ordered to my preference. I added the aliases to modprobe.conf to solved this issue. alias eth0 r8169 alias eth1 r8169 alias eth2 e100 Alan
