In my lab there are two computers and only one port from the wall. Firstly I used a switch to connect them, but only one computer can access internet. Someone told me that each port in the lab is connected with one MAC address. So what should I do to make the two computers both access the internet?

Somebody told me that I have to make one computer as the router and I have to install two net card on it, then I have to configure it as a router. However, I do not know why I should do it like that? May I have a ordinary router to connect them? What is the difference?

Please give some guidance or give me some manuals to read. Great great thanks!