RHEL4 tends to change network interfaces names

RHEL4 tends to change the names of network cards when there are more than one. If you had a NIC called eth0 during install time, it doesn’t mean that it will maintain that name after the first reboot. It could switch names with its friend, and be called now eth1, while the previous eth1 name is now eth0.

A solution using udev was posted in HPs forums, and can be reached directly through here. I will quote it:

Device persistence can also be enabled to ensure that the NICs identifying themselves as eth1, eth2, etc… always remain on the same hardware ports in case of a failure of a single NIC port. You don’t want your eth names to shift.

Upgrading to udev-095 from udev-039 that ships with RHEL4 is the smoothest solution, but that wasn’t an option for me. Using names other than eth0 – eth3 also wasn’t an option for me. Here is what we ended up using to get around udev-039’s inability to re-use eth0-ethx names.

Create a udev rule using YOUR MACS
Create an /etc/mactab file using YOUR MACS
Modify /etc/init.d/network to run nameif

/etc/udev/rules.d/20-net.rules
——————————–
KERNEL=”eth*”, SYSFS{address}=”00:0b:cd:69:c3:66″, NAME=”NIC1″
KERNEL=”eth*”, SYSFS{address}=”00:0b:cd:69:c3:65″, NAME=”NIC2″
KERNEL=”eth*”, SYSFS{address}=”00:11:0a:17:66:26″, NAME=”NIC3″
KERNEL=”eth*”, SYSFS{address}=”00:11:0a:17:66:27″, NAME=”NIC4″

/etc/mactab
————-
eth0 00:0b:cd:69:c3:66
eth1 00:0b:cd:69:c3:65
eth2 00:11:0a:17:66:26
eth3 00:11:0a:17:66:27

/etc/init.d/network
————————
(add right after
>>
# Check that networking is up.
[ “${NETWORKING}” = “no” ] && exit 0
<<)

# RDD: add ‘nameif’ usage; uses /etc/mactab
nameif || echo “nameif: reports error”