Author: Roman Serbski
Date: 26-10-00 15:32
You could use proxy (for example squid) and than add ACL restrictions for your users.
Squid is very flexible proxy program, it's possible to add time/traffic/authorization limits and etc.
Take a look at /usr/ports/squid*
For general info visit http://www.squid-cache.org
Second solution is to forward all outgoing TCP packets to your local website. In this case you should use firewall (ipfw, ipfilter etc.) - this solution is rather tricky cause you have to compile kernel with firewall features, and understand firewall rules.