Content Filtering in a LAN

[agent007]

Hi all,

IF, in a LAN all the PC's (workstations) have to connect to the internet via a s
erver (gateway), how do i configure content filtering for all the browsers on the workstations? Do I have to specify IP and port in the proxy settings of all the browsers? Also, if someone were to remove the proxy settings from their browsers then they'd be able to see the unwanted stuff correct?

thanks.

[Void Main]

I have addressed this on my personal LAN. There are a couple of different ways you can handle this. First of all, I assume you have a firewall between you and the outside world. I have my firewall set up to block traffic destined for port 80 outside of my network, except from my proxy server. You may want to block more than just port 80. If any of my internal machines want to access the internet, they must go through the proxy server so yes all browsers on my network are configured to go through the proxy. If they remove the proxy from the browser configuration they just can't get to anywhere.

The other way to do it is to set up a transparent proxy, then the browser does not have to be configured to use a proxy. Basically you have a firewall rule that redirects outbound port 80 traffic to the proxy port on your proxy server. I would like to do this but then my authentication will not work which for me is critical. I want to be able to identify who is browsing where and possibly restrict access based on the proxy user.

[agent007]

About authentication.....Will the authenticaton box come up everytime u try visiting a site?

thanks.

[Void Main]

No, it only comes up once in a browser session. That is, you open your browser, it asks you for your ID/password. It remembers your ID until the browser is closed.

[agent007]

hmmmm....Are there any resources which would give me some detailed info on how to setup these transparent proxies and stuff?

thanks

[Void Main]

Got this very good looking link:
http://squid.visolve.com/white_papers/trans_caching.htm

off of the main Squid site:
http://www.squid-cache.org/

But there are many documents out there on the net on how to do it. It's really pretty simple.

[agent007]

Cool links!! Thanks a bunch!

007

[Void Main]

If you are running Shorewall:

http://www.shorewall.net/Shorewall_Squid_Usage.html