DHCP trouble

[rebel]

Hello all..
I'm having some troubles setting up my ADSL modem for YDL-2.2
It simply doesnt wanna recognize my dhcp server, I have a D-Link ADSl 
modem and I'm not sure if its my modem or the system..has anyone else 
had troubles like this?
I had an alcatel modem before, which I used for YDL 2.0, and it worked 
fine..is there no way to configure stuff like in the mac os 9 TCP/Ip 
control panel? I think it may need my domain name to work (telia.com)
I am using an iMac DV 400..
Any help would be greatly appreciated..thanks!