From: Harshal p.harshal@gmail.com Date: Tue, 9 Aug 2005 19:21:31 +0530

hi, i have machines here with 2 ethernet cards each. the card that is inseted in the PCI Exp. slot always detected as eth0 and the one onboard eth1 except on the machine where i have 3 NICs. there the onboard gets eth0, PCI exp. NIC as eth1 and the last one inserted in normal PCI slot as eth2.

how does OS decides which card to call eth0 or so on?

In RedHat/Fedora (as well as their clones) you can use MAC address to bind eth0, eth1 etc. names to specific NIC. Useful when all the NICs use the same driver. Take a look at the /etc/sysconfig/network-scripts/ifcfg-eth* scripts.

HTH