Firewalls Explained
A firewall is like a brick wall between your computer and the Internet. Its main purpose is to protect your computer from attackers on the Internet by blocking services that you don’t use. For those that you do use, you have to punch a hole in the firewall. This hole allows you to use the Internet like normal with the services that you use. For instance, you punch a whole so you can check your email, so you can surf to a website, or use an Instant Messenger. There are two common types of firewalls.
1. Hardware firewall (recommended) – This is a physical device that you connect between your computer and Internet connection. The most basic and most common hardware firewall is a router. For the average use this is all that is needed. The router works as a firewall by dropping anything trying to go from the outside to the inside unless a request was made from the inside first. This requires no configuration on your part. There are more advanced firewalls such as the Astaro gateway and software that you put on a spare computer such as SmoothWall. These allow for much more configuration and options.
2. Software Firewall – this is software that you install on your computer. It works in a way similar to the hardware firewall, but it does it all inside of your computer. This kind of firewall adds the additional protection of asking you what kind of traffic you want going out of your computer. But, this could also be somewhat annoying because it pops up a window asking if you want to allow a certain program to access the Internet. Software firewalls can also be easily turned off by viruses and other malware (bad software). All modern Operating Systems come with software firewalls built in. After Windows XP SP2 the software firewall in windows XP is on by default. The same is true for windows Vista and windows 7 when it comes out. You can turn the firewall on in OS X in the System Preferences. It is not a bad idea to have the software firewall turned on for a couple of reasons. If a computer on your home network (if you have more than one computer at home) is infected with a virus it could potentially spread to other computers on your home network even if you have a hardware firewall because all of the computers would be on the inside of the firewall. It is also a good idea to have your software firewall on when you bring your laptop to other networks for this same reason.
-Zach
