I changed out a NIC card that was the exact same make and model.  The setup process for Ubuntu 11.04 was very seemless and easy so I figured it would be smart enough to setup up the replacement card.  However, it gave the replacement card a new name of eth1 where all my scripts make reference to eth0, not to mention everywhere else in the OS eth0 may exist.  Am I forced to track down every eth0 reference and change it to eth1 or is there a way to rename the replacement card back to eth0?
Replacing identical NIC cards creates eth1 instead of using eth0 in Ubuntu
ubuntu;ethernet;replace
Check udev config files.A file like this:    /etc/udev/rules.d/70-persistent-net.rulesties the NAME (ethX) to the Mac address. You probably have the old cards MAC tied to eth0. Remove its line and change the new card to eth0.