Click the SuSE (Start) icon bottom-left, then goto System, then YaST.
Type in your root password and click OK.
Click 'Network Devices' in the menu, and then 'Network Card'. Select your network card and follow the on-screen instructions.
I am not sure if the layout of SuSE 7.1 (i am using Suse 9.1 Personal) is the same as mine, but it should be similar enough.
Have you thought about upgrading/installing a newer version of Linux?