Refusing Internet access after a certian time in Windows 2K Server

Hello, everyone.

A friend of mine and myself were asked to set up a domain for the new students at our school. We set up the PDC on Windows 2K Server (no internet access yet so we are NOT running the latest service pack) with DHCP, got Active Directory and DNS installed and operating and created our users.

The students require internet access for their labs and, once we get a second NIc for the server, they will access it through our server. their instructor has requested that each day, at lunch, their Internet access be refused.


Our original solution was simply to unplug the cable to the 'Net, but we were curious: Is there anyway to block Internet acces after a certian time?

Thank you for your help.

 

Policy would be a easy way to do it.