Set up internet sharing on 2000 pro

How do I know the addresses ect to be filled in at the network card tpc/ip properties on my internet server. I can connect to the internet through my first card, but forgot my settings for the second net card after a crash and now can’t get back up. All of the settings are still ok on my work stations, but on the 2000 pro computer I use as an internet share server I am dead in the water.