It's called Pfsense check it out with a google search, pfsense.org is the official site.

http://www.smallnetbuilder.com/security/security-howto/31406-build-...
Hear that sound? That is someone rattling your doorknob. If they are able to break in, they will ransack your home, rifle through your private papers, correspondence, bank statements, photos, and if lucky they’ll find your club memberships and credit cards - your identity. They may even plant listening devices. If you lived in a bad neighborhood, you’d put in high quality locks and maybe an alarm system. The problem is, on the net, everywhere is a bad neighborhood.

What stands between you and this happening on the internet is generally your router, which is designed more as a doorway than a lock. Consumer grade firewalls, either software or hardware, can act as a lock or gatekeeper. But to truly turn back the faceless attacks (even if they would just find pictures of your kids), you need a dynamic firewall with intrusion detection; the kind of 1U firewall server appliances usually found only in corporate data centers (read: expensive). Devices that generally start at about $3K; a Cisco PIX firewall starts at nine.

We’ll show you how you can put together your own firewall/router with all of the capabilities of high-end gear using open source software and inexpensive components. There are a significant number of open source distributions available for homebrew router/firewall builds. We chose pfSense for its outstanding built-in functionality, active support forums, first class documentation and overall maturity. Most significantly, beyond rich routing functionality, pfSense offers firewall and intrusion detection/prevention well beyond that of the mere mortal router.
From>>> http://www.smallnetbuilder.com/security/security-howto/31406-build-...

(TLS-) I use to use Smoothwall Express to secure my network and there is nothing wrong with SWE it works just fine. I had no break in's that I know of but I wanted a bit more and being a bit geeky wanted the best available. I consider PFsense the BEST there is in open source firewalls for many reasons including but not limited to: DDOS survivability greater than Linux based firewalls, ease of adding features, type of features including SNORT which is the Intrusion Dection and Prevention System.

It's not hard to set one of these up with one of the older PC's you have sitting around collecting dust, assuming you where smart enough to keep it!! If you want to go further you can add anti-virus capability's, again for free through the add packages tab. http://www.smallnetbuilder.com/security/security-howto/31433-build-... link to helping you build your UTM: Unified Threat Management is straightforward: on the outer reaches of your network perimeter, you install an appliance that stops all possible threats to your network, an über firewall, as it were.

Enjoy! don't be lazy try to build one and if you run into trouble IM HERE ASK ME A QUESTION!

'UTM appliances' will supplant firewalls

Growth good all-round but all-in-one security systems are the rising stars.

By John Dunn | Techworld | Published: 09:34, 24 September 2004The basic building block of today’s network security is the firewall but two market analyses from research company IDC offer compelling evidence that this is about to change.