Ubuntu/Debian as internet gateway

[tommyboy180]

Hi,
I have a project that I would like to do. I would like to add a server to my network that would act as a gateway that would have anti-virus/anti spam features.
Just to tell you what I am looking for let me explain that I already have a main router that I am not willing to replace. I would like to have my connection look like: Internet -> main router -> THIS project -> switch -> clients.

I would also like to make this gateway a mandatory gateway (two nics)

My network is 192.168.1.0 on 255.255.255.0

My only problem is that I don't know where to begin. What I would like to find is a program that could inspect packets for information that is harmful, and how to implement it on a software/hardware level.

Let me know if I am wasting time, or if this can't be done. Thank you.

[falko]

Originally Posted by tommyboy180

Hi,
I have a project that I would like to do. I would like to add a server to my network that would act as a gateway that would have anti-virus/anti spam features.

Are you talking about email? You could set up fetchmail or getmail on that box to fetch emails from your users' external email accounts ( http://www.howtoforge.com/debian_etch_fetchmail & http://www.howtoforge.com/debian_etch_getmail ), and then you install Postfix and integrate amavisd_new into it: http://www.howtoforge.com/amavisd_postfix_debian_ubuntu
Afterwards you tell your users to fetch their emails directly from the new server instead of from the external mail servers.

[tommyboy180]

Actually no,
I'm looking for a solution to better internet security. A server that will block spam and viruses that you might pickup browsing the web. Like squid with packet inspection. But a server that will handle all public traffic, not limited to web browsing. The solution that I am looking for doesn't need to have anything to do with email services. And if there is nothing like this, is there a way that I can have a server that will handle all public traffic like the illustration in my first post? Thank you for your reply.

[lando]

Maybe using Squid and Dansguardian and direct all traffic through the webfilter?

Can you explain further what you mean by "all" traffic, do you mean pop3, smtp, ftp, www etc?

[tommyboy180]

Yes, thank you lando.
When I say all traffic I meant every packet going to the public side to include all that you listed. What I am primarily concerned about however is www traffic (secure and non-secure). My clients do use ftp and pop/smtp; however www traffic generates most of the network usage. I was looking for a way to utilize anti-virus and anti-spam software with the squid proxy. We already have a working squid proxy being used.

Thank you for your help.