Firewall and Security

In today’s world, firewalls and data center security are as necessary as locks on doors and windows. Without some device or software to handle security between your computer and the internet, the Sans Institute’s Internet Storm Center reports that the computer will be under the control of a malicious coder in less than 20 minutes. That was in 2004. You can be sure it’s at least that fast today.

Microsoft’s Windows Firewall has undergone extensive improvement since its implementation in Windows XP. The new version that comes with Windows Vista is infinitely more configurable. In addition to the rather nebulous “on” or “off” settings which you had in XP, you can now configure specific rules for programs, ports, or protocols and apply them to different network profiles.

Perhaps even more significant is the addition of outbound traffic controls in the Microsoft Windows Firewall. This is a giant leap forward for this utility and makes it a worthy security option for the home user, especially in view of it‘s partnering with Windows Defender.

In addition to the Microsoft Windows Firewall, for residential scale networking I like to be very familiar with and employ the hardware firewall included in many home networking routers and wireless access points. The two most common of these are the Linksys and D-Link products for home networking. These products often have a web-based configuration utility that allows you to set up specific port behavior and program exceptions, much like a more expensive product, in a way that is accessible to the home user.

Just as “least privilege” is the best practice for user objects, your network should be set up for least access. That is to say that you should only open the ports you absolutely need. An open port in your firewall is like an open window in a locked house. What? You say “but I require a password for remote desktop port 3389.” Ok, so that’s like a screen in the open window in a locked house. Every opening in the firewall is an additional venue for the malicious coder to get control of your computer and your personal information, so it’s best to keep them all closed. If you are a gamer or employ some other application that requires port forwarding or otherwise opened ports, consider closing them immediately after your session.

Once you have the firewall where you think you want it, it is important to test it to be sure. “Testing Proves Testing Works,” as they say. Security Metrics is one of several online sources for security testing. The Free Port Scan and Firewall Test page of their web site will determine your public IP Address and use that to scan your computer for open ports or possible vulnerabilities. It’s basically a self-inflicted port scan from the internet. This way you will know for sure what is open on your network. A tool like this should be used every time a change is made to the firewall configuration on any network.