Nah, this doesn't have to do with a bootloader. In /etc/sysconfig/networking-scripts there is a file called ifcfg-eth0 or somesuch... you can hand edit that to suit, or...
I forgot about netconfig for a minute that's why the long is before the short. This is going to make it so that the machine will try for a dhcp lease from the router for 1 minute on boot. If you're out of range, or the router is off, its still going to sit there like a dink for a full minute (its not hung, that tricks a lot of people). If the card is external, you can just yank the card before booting. Or...
You can edit the file /etc/pcmcia/network.opts and hopefully that will work. The distros haven't been keeping up with the advancements in pcmcia lately and its a little bit of a juggle to get things tweaked for ease nowadays.
3-4 ways to do anything, fun eh?