What are Firewalls?

Firewalls are tools to block access to and from your computer's ports. If you think of your computer as a castle, then the computer's ports are like the doors and windows leading in and out of your castle. Unfortunately, many times these doors and windows are left open, sometimes allowing hackers to use them to get into your computer.

Like a wall surrounding a castle, a firewall puts a barrier between your computer and the Internet. Although the doors and windows on your computer may remain open, the firewall makes sure nothing goes in or out without your permission. The best firewalls monitor both incoming and outgoing Internet traffic on your computer.

 What firewall software is available?

A number of vendors offer firewall products:

• Zone Alarm Basic Version is free and highly recommended. (Look for the "Free" version - you probably don't need the commercial versions for sale).
• BlackICE (commercial)
• Norton Personal Firewall (commercial)
• McAfee Personal Firewall Plus (commercial)
• Windows XP comes with a built-in firewall, although it monitors only incoming, not outgoing Internet traffic. Learn how to activate the Windows XP firewall.

 Tips on Using Firewall Software

• Once installed, your firewall may occasionally ask you whether you want to allow certain programs to access the Internet. Read the description of the program carefully, and if you feel the program has a legitimate reason for accessing the Internet (such as Internet Explorer or Outlook Express), answer "Yes". If you're unsure, say "No".
• Your firewall may pop-up windows alerting you when it blocks a suspicious attempt to access your computer. Don't panic! It is fairly common for hackers (or just curious people) to scan a wide range of computers, looking for open ports. Rest assured that your firewall is doing its job, and turn off the pop-up notifications if they get too bothersome.