Renumber ethernet interface on CentOS Linux to eth0

When changing network cards (either physical or virtual) it’s often the case that the new card gets a higher interface number. For example, your old card was identified as ‘eth0′ and the new card gets identified as ‘eth1′. This may cause problems in your scripts (networking scripts, iptables settings, network traffic counters, etc.). But it’s also not as clean as you would want (you’re obsessive about these things, admit it!). Fortunately, we can easily renumber the ethernet interfaces!

http://www.syn-ack.org/centos-linux/renumber-ethernet-interface-eth0/