Patrick J Smith asked:
There are two types of firewalls, hardware and software. A software firewall resides on your machine, while a hardware firewall is a standalone device that connects to your network. Both do the same thing; they attempt to stop unauthorized traffic from entering or leaving your network or your PC.
This section provides instruction for setting up a personal firewall, which is a software application that you can use to protect your computer. In my opinion, even if you’re running hardware firewall on your network every computer you own should have a personal firewall installed. There are several on the market, including a couple that are free for home use.
While a hardware firewall is useful for protecting your network from threats that originate from the Internet, many threats originate within a WLAN, from wireless attacks or access points. A hardware firewall provides no protection against wireless intruders because these attacks originate on the wrong side of the firewall. This is why I stress the use of software firewalls to protect individual computers on your WLAN.
Installation of a personal firewall is usually easy and is handled by an installer program or wizard. Exact installation instructions differ among firewall applications but there are a few common points that you should consider when installing any personal firewall.
1. Install a personal firewall after you have completed the setup of your WLAN. You want to be sure that everything is working properly before installing the firewall, so that you will know if subsequent problems are due to the firewall blocking connections or if there is a problem with the WLAN configuration.
2. Do not install more than one personal firewall on a computer. Running multiple firewalls does not make your computer more secure. The applications are likely to interfere with one another and crash your computer. They might also prevent each other from operating correctly, leaving your computer vulnerable.
3. Gather MAC and IP addresses from your WLAN clients before installing. Most personal firewalls install with a default setting that blocks all traffic from entering your computer. If you are sharing files or peripherals (printers), you need to tell your firewall which computers to let through. Depending on the firewall you are using, you need the IP or MAC addresses of computers that you want to allow accessing your PC.
Personal firewalls are highly configurable, and many block outgoing as well as incoming unauthorized connections. You may find that your firewall is “noisy” at first. This means that you may see a lot of warnings and dialog boxes as each application tries to connect. Most firewalls quickly learn which of your applications should be allowed to connect to the Internet and which shouldn’t. If you see a warning that a particular application has tried to access the Internet, do the following:
1. Determine what the application is. If you don’t know what it is or what it does, look up the application’s name through a Google search. Chances are you have a lot of spy ware on your PC that you don’t even know about. If you don’t know what an application is, don’t let it access the Internet.
2. If you know what the application is and what it does, and you feel comfortable letting it access the Internet, then configure your firewall to let it pass.
Insider insight: You are running Windows XP then you already have a firewall on your computer. Windows XP comes equipped with the Internet Connection Firewall ICR. ICF does a decent job of blocking incoming connections to your PC but does not block outgoing connections.
Once you have installed your personal firewall, test it by visiting Gibson Research Corporation’s “Shields Up!!” utility. Shields UP!! is an online utility that tests the effectiveness of your firewall.
