Require authentication to use the internet

Question

In my college's computer lab, I want to configure the computers in such a way that whenever a user tries to use the Internet in that lab they are asked to authenticate (provide a username / password) themselves through my computer. Only then they are allowed to use the internet.

I want to implement this using networking techniques and concepts of some kind -- what would be appropriate?

Answer 1

Setup a proxy server like squid. Require authentication. Configure the browser on all the computers to use your proxy server. If possible use a firewall to block all http connections that do not go through your cache.

Here is a section from the squid faq that describes how to use authentication.

Answer 2

I think what you are talking about here is an authenticating proxy server? Microsoft's offering is the ISA Server, but there are also plenty of free ones out there.

Answer 3

Given how you asked the question, I suspect that this approach is beyond your authority and access to implement, but I believe one of the most standard, secure, and compatible methods to do this is through 802.1X, the IEEE standard "port network access control" protocol.

Be warned that it involves implementing many nontrivial services, like a proper PKI and RADIUS setup, so it is not an easy road.

However, it will be more secure and much more reliable than a simple HTTP proxy / captive gateway system.