Edu Internet blocking

[Michael A Hamblin <michaelh@utdallas.edu>]

What software is available for Linux that can be used for blocking or
monitoring the Internet (or the Internet as educators see it, the Web)?
Beside firewalls, caching proxy servers, and the like which I know are
available for Linux, I had a couple other thoughts but I am not sure what
options are avaiable.

Transparent Caching proxies... so no proxy setting have to be made on the
web browser, making it easier to support.

Blocking specific sites... this could be done through a transparent proxy,
but there would have to be a database of sites which are categorized for
blocking/unblocking. Example of what I'm talking about...

My old school district has filtering software called WebSENSE, which does
blocking and maintains a database of 350,000 sites which are categorized
(adult entertainment, alternative journals, cults, drugs, gambling,
hacking, militancy, personals, pornography, racism/hate, sexual
lifestyles, tasteless humour sites, weapons, violence, web chat) and the
level of blocking can be controlled by the admin.  This is different that
word bsed searches b/c research on the effects of say alcohol may end up
blocked in various ways.

Trouble is, I know of no Linux alternative, not to mention the price tag
for such services.

--
Michael Hamblin            http://www.utdallas.edu/~michaelh/
michaelh@utdallas.edu      http://www.ductape.net/
UTD Linux User Group       TCS HelpDesk (x2911, assist@utdallas.edu)