Re: [CentOS] Ethernet puzzle

Remember, udev's rules lists FOUR devices. There are only THREE.

What does the BIOS say about ethernet devices?

Does the motherboard have a management interface card with its own ethernet port, perhaps potential but not actually installed?

An IPMI may have its own MAC, but share a physical port with the main NIC. If you are using this as a firewall, make sure to not have an IPMI port facing the internet.

You may have a MAC address in one of your ifcfg-eth* files that does not _exactly_ match the hardware. Sometimes, it can be case-sensitive. pushd /etc/sysconfig/network-scripts/ mkdir BACKUP mv ifcfg-eth* ./BACKUP/ I would take out all the add-on cards and see if this extra MAC stays around. Put the other cards in one-by-one till found.