Dear all,

I have been assigned a task to implement a free open source content filter having feature of web, email, instant messaging etc. If any one has the information or worked on this type of product please share it. Eagerly waiting for the reply.

With regards

Harry

Keep waiting. There is no such thing that will work 100% of the time, and do everything you're saying, for ANY platform.

You can do bits and pieces of this, as a quick Google search could tell you. Squid proxy server with Dansguardian can help with web proxy/content filtering. Email servers like postfix/sendmail with Dovecot and ClamAV for antivirus can give you email and scanning. You can implement a Jabber server on Linux to provide instant messaging.

However, the way your question reads, it looks as if you want to FILTER all of the above. You can filter bits and pieces, but can't do it for email or IM's, simply because you'd never get the 100%. You can block gmail/yahoo mail/etc., but what if someone uses something else? Or has their OWN web server that has their mail? The list will get really long, really quick, and you'll always miss some. Same with IM's...you can block the protocol/port at the router, but they can tunnel it through via HTTP proxy, and get past. Or hit a web page with a Java applet and chat all day long.

If you are planning on filtering all these different types of access then your best bet (as stated above) will be to set up a proxy server. Then block off any ports which you don't want to use (more specifically open open specific ports you do want to use). Then you will need content filtering on communications which you allow (http etc) - various methods for this, all have their pro's and con's. Simple content filtering - if it contains the word "sex" then don't allow etc, very easy to set up , but very easy to bypass! Packet inspection, more difficult to set up, but more difficult to bypass.

Dear friends,

Thanks a lot for giving such detailed answere. Actually I can put no. of content fiters for various sort of scanning (e.g. web,mail or instant masseging). Presentally we are using different content filters for web and E-mail but they are vendor products. Can we use Postfix/Sendmail as only content filter with the existing Mail domain (e.g Microsoft, Lotous Domino)or there are other email specific solutions. Please suggest specific content filter solutions for specific tasks.

With Regards,

Harry

I did in my first post, if you read it...sendmail/postfix, spamassasin and ClamAV for mail. Web is Squid w/Dansguardian. Block messaging with IP tables or at the router.

Dear TB0ne,

Thanks for giving such precious information. Please give me some references where I can find exact & accurate configuration document or templates.

Thanks & Regards,
Harry

Have you tried this: http://www.untangle.com/

what about this..

http://www.instructables.com/id/Set-...ps-with-Ubunt/

scroll to the bottom, 4 easy steps.

what do you think?