Help. Motherboard changed. Everything is fine except eth0.

[Tom Horsley]

On Wed, 29 Dec 2010 23:39:25 -0200
Lucélio Gomes de Freitas wrote:

> How to recognize the eth0 on board?   There is only this eth0(on board) on
> this machine.

Two likely problems: /etc/udev/rules.d/70-persistent-net.rules
names the interface, so it still has the mac address for the old
NIC as eth0, and there is probably now a new NIC named eth1 for
the interface on the new motherboard. You can edit the file to
remove the old NIC and rename the new NIC, or simply delete it and
let the next reboot re-generate it.

The second problem is the /etc/sysconfig/network-scripts/ifcfg-eth0
file, which almost certainly has the mac address built into it.
You need to edit it as well to get the new mac address that matches
the new NIC into it.

Reboot after fixing both files, and eth0 should be back and
running on the new NIC.