Binding Network Devices

You can manually force the assignment from a network card to what device comes up as (eth0, eth1 ...), by changing the udev rules. You can manually edit this file:

           /etc/udev/rules.d/70-persistent-net.rules

This file maps MAC address to device name.

Example

SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="00:1d:60:b5:43:66", ATTR{type}=="1", KERNEL=="eth*", NAME="eth0"
SUBSYSTEM=="net", ACTION=="add", DRIVERS=="?*", ATTR{address}=="5c:d9:98:af:21:43", ATTR{dev_id}=="0x0", ATTR{type}=="1", KERNEL=="et1"

This file maps the card with MAC 00:1d:60:b5:43:66 to eth0 and the card with 5c:d9:98:af:21:43 to eth1.

If you want to reverse the assignments, switch eth0 and eth1 at the end of the entries. Or delete one of the entries.

If yo still do not have network functionality (system may boot complaining about a MAC mismatch on eth0) you may need to edit this file:

           /etc/sysconfig/network-scripts/ifcfg-eth0

Example

HWADDR=00:1d:60:b5:43:66

You will need to adjust the HWADDR to match the MAC address of the card you wish to make eth0. Note: if you wish to keep eth1 active, you will also have to edit ifcfg-ith1 as well.

These changes will only take effect after a reboot.

Please exercise care. Improperly modifying these file may render your system without network or even not boot properly.