Linux – what is the use of /etc/udev/rules.d/70-persistent-net.rules file in rhel

try getting more recent kernel - maybe etch-n-half or even upgrade to lenny.

I'm using Slackware 10 as a reference, so there may be a slight variation in configuration files.

/etc/rc.d/rc.inet1 is the init script for the network interface, which is where I would begin for customizing any start time network configuration.

It looks like this init script does not have any logic for specifying the hardware address. However, a simple modification should be able to enable this functionality.

As far as your specific question, I think you're asking if specifying NIC1 as eth1 in udev will result in NIC0 defaulting to eth0? If so: probably, but I'd recommend testing this. Otherwise, please clarify.