[Wlug] DNS question...

Quick question I can't seem to find a google answer on. I've got a machine that gets it's IP via DHCP. Now on our network, the DNS name is pulled off the machine and auto registered. However this machine won't push its domain name. Any ideas where a) the setting for this might be b) any manual step you can use to update the DNS name? I looked at the nsupdate command, but I'm not sure that's the right command. Talking with the network guy, he recalls there being a graphical tool for Linux that would let you do this. Thanks, Tim.