| To understand what a computer firewall is, it helps to | | | | they're not sure. |
| understand what real firewalls are. Firewalls help to | | | | The first time a particular program accesses the |
| prevent fire from spreading from one section of a | | | | Internet, you will be sent an alert, and you can modify |
| building to another. The firewalls themselves are simply | | | | the firewall by either allowing or disallowing that |
| structures that can limit access from one side to | | | | particular program to access the Internet. Don't |
| another. Computer firewalls are exactly the same | | | | automatically allow access to the Internet for any |
| because they restrict the flow of program instructions | | | | random programs. If you don't recognize the program |
| and the flow of data in and out of a computer system. | | | | that's requesting access, you should disallow the |
| There are basically two kinds of firewalls - hardware | | | | access. If you're installing software, most software will |
| and software. Although it seems as if these are two | | | | specify which firewall settings are needed to run |
| totally separate items in fact they must exist together. | | | | specific programs so you know which programs you |
| Hardware can't do much without the extra software it | | | | can allow through the firewall and which you should not |
| requires to run, and software simply doesn't exist | | | | allow. |
| without the hardware. | | | | Your computer has several ports, which are numbers |
| Hardware firewalls are usually used within businesses | | | | used by network software to distinguish Internet traffic, |
| or large companies because they control the flow of | | | | and hackers can get access to your computer |
| traffic between networks. For example, a corporate | | | | through open ports. If a hacker finds an open port he |
| firewall might control traffic between the corporate | | | | can use that open port to transmit a worm which can |
| network and the Internet. When firewalls are in use | | | | then infect your system to give that hacker control |
| incoming traffic from the Internet can be restricted to | | | | over your personal computer. Firewalls automatically |
| areas that have been identified as public use areas or | | | | protect most open ports and watch for these kinds of |
| to specific computers on that network. | | | | attacks. |
| Sometimes corporate networks will also use internal | | | | In fact, if you buy a good firewall program, you can |
| firewalls, which can keep resources restricted to | | | | even use that software to hide the very existence of |
| specific groups of people or computers, or to prevent | | | | open ports, not just close them. This means that |
| viruses from spreading from one area to another. | | | | instead of a hacker learning that there is an open port, |
| Software firewalls, which are more commonly used | | | | but it's protected by a firewall, he will not see that |
| for personal computer use, are slower than hardware | | | | there any ports available at all which in effect renders |
| firewalls and use resources from your personal | | | | your computer invisible. |
| computer. | | | | Even though firewalls do the work that we wish we |
| Because firewalls can control both outbound and | | | | could do ourselves -- keeping out the unwanted |
| inbound traffic to the Internet they can help to prevent | | | | visitors to our personal computer system -- they are |
| access your system by viruses or hackers. If you | | | | not totally perfect. Firewalls are vulnerable to virus |
| have antivirus software you might think that the there's | | | | attacks and attacks by Trojan horses and worms. |
| no need for a firewall, but the reality is the two must | | | | The viruses can modify system settings and take |
| work together. Because e-mail programs, browsers, | | | | down the firewall and make your computer vulnerable |
| and even antivirus software require connection to the | | | | to hackers. |
| Internet, it's important that a personal firewall is set up | | | | This is why, when you install a firewall, it helps to have |
| to allow certain kinds of traffic while disallowing other | | | | solid antivirus software as well. Keep your antivirus |
| kinds of traffic. | | | | software up to date, and you will also be protecting |
| Firewalls can become as smart as you allow them to | | | | your firewall as well as the other data on your |
| become. For example, they can learn which programs | | | | computer. |
| access the Internet freely and they'll also ask you if | | | | |