What’s a firewall?
Find out how this program can protect your computer
By Charles Mandel
Calgary homemaker Venora Geppert vaguely knows a firewall offers some kind of protection, but she doesn’t have one on her computer, doesn’t know why she needs one and doesn’t know how to install one even if she were to get one.
Geppert isn’t alone. Most people haven’t the first clue about firewalls, but like Geppert, once they find out, they’ll likely want one immediately.
Firewalls block outside users from getting into your computer, much like physical firewalls prevent fires from spreading from one area to another. A firewall program is different from a virus protection program, which only screens for computer viruses.
Once Geppert learned more about firewalls, she said she’d certainly consider getting one. “Just reading all the stories, how people can steal not just your money, but your identity, it really would be a concern to me,” she says.
Figuring out a firewall
High-speed Internet connections, such as cable and DSL, make users’ computers act like an open door to the Internet, since they’re on all the time. Dial-up is less vulnerable because Internet service providers (ISPs) allot dial-up users with dynamic Internet Protocol (IP) addresses, shifting their Internet connections to whatever is available at the time.
Hackers probe all the addresses of ISPs, looking for vulnerable computers. Once they find an available computer via an open port (normally used to receive e-mail or web services off the Internet), hackers can deposit Trojan horses — programs or software that might send information back to their computer from yours; place files from their computer on yours; or even manipulate information on your computer.
“It’s nearly a 100 per cent chance if you have a cable or DSL modem that you will get a hacker attacking your computer,” says San Diego-based Wally Wang, author of Steal This Computer Book 3 (No Starch Press, 2003). “I’d say there’s very little chance they’re going to do any damage.”
But is it a chance you really want to take?
Locating the firewall
Windows Vista comes with a pre-installed firewall that helps provide more protection from Internet-based attacks during the computer’s start-up and shutdown processes. Windows Firewall automatically sets restrictions on what information is communicated from your computer to the Internet and allows advanced users to quickly set different security profiles for different locations.
The Windows Firewall icon is located in the Control Panel. Clicking on it displays the status of your firewall and gives you the option of turning it on or off.
Using different safety measures
Henry Stephen Markus, creator of Home PC Firewall Guide, advises using “layers of security,” which means not only purchasing a personal firewall but also paying an ISP for online spam and virus protection to help reduce unwanted mail.
Wang warns trusting security to a firewall is an act of faith, since many hackers know how to get around them. Markus agrees that firewalls aren’t perfect; however, most Internet users can achieve a reasonable level of security at a low cost, and that’s better than no security at all.
