Security

Firewall Basics

By Jennifer Martinez

They keep the bad stuff off your computer and the private stuff safe. They make connecting to the Internet safer by automatically blocking intruders who try to access your computer. If you don't have one, you should: a personal firewall. But don't let the techy term scare you. Personal firewalls are easy to install and manage.

What does a personal firewall do?
Like a virtual sentinel, a personal firewall is a piece of software that keeps constant watch over your computer.

A firewall monitors anyone or anything that tries to access your computer over the Internet, asking "Who are you and what are you doing here?" And it grants access only when it's satisfied with the response. It identifies and blocks known Trojan horses, viruses or worms. And it monitors all outgoing traffic, alerting you when an unauthorized program attempts to hijack your computer to send spam, for example.

Antivirus software keeps out viruses, worms, and Trojan horses, but a personal firewall stops hackers and other intruders from infiltrating your computer. And working together, these two technologies can thwart attacks that use a combination of malicious code and hacking techniques. Simply put, personal firewalls are a like a gatekeeper that monitors and blocks undesirable or dangerous Internet traffic. Think of it like a dead bolt on your front door.

Do you need a personal firewall?
Unfortunately, if you're on the Internet you're a target for viruses, hackers and identity thieves. In fact, hackers scour the Internet for unprotected computers. When they find one, they attempt to break in. And whether they're after your data or just out for a voyeuristic romp, you don't want them there. Meanwhile, some cyber-criminals hijack random home computers and use them as cover to initiate more serious crimes without your knowledge. When a hacker uses your machine to launch an attack, you can become a suspect in the crimes he's committing.

While network and operating system firewalls offer some protection, they're not enough. Most operating system firewalls control only incoming Net traffic, however; they don't do anything to stop malicious code that sends information from your computer. And hackers can find ways behind home network firewalls. Meanwhile, when you connect to a public Wi-fi hotspot, the firewall on your home network offers no help at all. A personal firewall, on the other hand, protects your computer or laptop at all times.

Are personal firewalls difficult to use?
You don't have to be a network administrator or computer expert to install and manage a personal firewall. You can buy a personal firewall off the shelf and install it just like any other piece of software, simply by following the prompts on the installation CD. Once it's up and running, the typical firewall has a central management console for changing protection levels, monitoring traffic, and responding to alerts. In the end, most personal firewalls are no more difficult to use than the average word-processing program, for example.

And installing a personal firewall is worth the effort. It will keep the unwanted out, let the desirable in, and constantly keep watch for suspicious activity.  It makes your computer less visible to hackers and protects you when you're on the go.