Adding aliases in Redhat

I am using a firewall which has a number of aliases on each NIC.
Currently I am configuring these, and running mii-tool on the one which
just can't negotiate with one switch, from rc.local.

The problem is that I would like to be able to have
service network restart
be non-destructive and run the startup script. I thought it was a simple
as editing the /etc/sysconfig/network-scripts/ifup-ethX script to finish
the job. Doesn't look as if that's it, the script isn't being run.

Can someone point me to the "right way" to deo this? I can obviously
brute force it with a script, but I'd rather understand why the script
isn't being run by the normal Redhat operations.
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