The following distributions have been suggested on the mailing-list. They are specialized as firewalls. Configuration is easier than with 'all-purpose-distros'.

• Coyote Linux - http://www.coyotelinux.com/products.php?Product=coyote
• IPCop - http://ipcop.org/
• Smoothwall - http://smoothwall.org/
• Fli4L - http://www.fli4l.de/e_index.htm

Since this service should run on a separate box, they do not need to provide much. They usually run from floppy or CD and are able to run on small/old/silent/… hardware. If your business depends on internet-access to be highly available, you should not use old hardware. But if you can easily cope with not being able to access the internet for the time it takes you to replace the box, you can re-use your ex-desktop.

Often it is the easiest to use a regular DSL-router appliance for this task. They usually come with basic firewalling and integrate some services like DHCP.

I am not endorsing any of these companies, but in my business, I use a regular Netgear RP614 which serves me well. I have been playing with the thought of buying a Pyramid Ben-Hur, but I think that I will be using ZoneCD instead (see Restricted internet access)

You can check your firewall using ShieldsUp?!!.