Here are the basic steps.
First, shut down the machine and install the card. Make sure you use a ground strap and be careful of static. One little zap can fry the machine. Put the machine all back together.
When you start the machine back up, stop it at the open boot PROM prompt. That's the "ok" prompt. Type in "[tt]boot -r[/tt]. This will do a reconfigure boot.
Then, you need to know what kind of NIC this is. I believe you can do an [tt]ifconfig -a[/tt] at this point to see the installed cards. If the new card is the same as your old one, and the old one is at [tt]hme0[/tt], then the new one would be [tt]hme1[/tt].
Assuming this is the NIC type (for this example), you should already have a file called [tt]/etc/hostname.hme0[/tt] that contains the hostname. Create a new file called [tt]/etc/hostname.hme1[/tt] that has a different hostname. Add this new hostname to your [tt]/etc/inetd/hosts[/tt] file with the IP address that this card should be assigned.
Then, reboot the machine ([tt]init 6[/tt]) to make it all take effect. Once it's back up, use [tt]ifconfig -a[/tt] to see that both interfaces are there. From other machines try pinging and logging onto the new IP.
At this point, the machine has two hostnames defined. The file [tt]/etc/nodename[/tt] defines the true name for the machine.
I typed this from memory, so I'm sure some details might be off. But this is basically how it's done.
Hope this helps.
