Firewall Software

A firewall is an integrated collection of security measures designed to prevent unauthorized electronic access to a networked computer system. A firewall inspects network traffic passing through it and denies or permits passage based on a set of rules. Its basic job is to regulate traffic from a computer network such as the Internet to a computer and vice versa. In many ways firewall software is similar to a building firewall that blocks the spread of a fire to adjacent structures.

Firewalls rely on rules that define which network communications are allowed to pass into your computer and which are blocked. Setting up these rules is no easy task. If the rules are too lax, you may as well not have any firewall; as Cole Porter would say, anything goes. On the other hand, if the rules are too strict, you don’t get what you need from the Internet. An unplugged computer may not be a security risk but it doesn’t give you anything.

Make sure you install firewall software on your computer.

What about personal firewalls, firewalls designed for the home user? Here are some of the features that you might find useful: The package should alert the user about outgoing connection attempts that may have been initiated by a rogue program. The software should let users control which programs are allowed to access the Internet. It should not respond to unsolicited network traffic, in essence hiding the computer. It’s important to monitor and regulate all incoming and outgoing Internet users. The software should inform the user about applications that try to connect to the computer. This raises a real problem. The user may not be able to answer when the firewall asks which connections should be allowed and which should be suppressed. Once users find out that a desirable communication was blocked because they clicked No, they are tempted to click Yes automatically to avoid missing out on anything.

You might think that it’s OK to send out all traffic upon request. But what if a vicious program has compromised your computer and requests it to send out data such as your social security number and credit card information? Shouldn’t these communications be blocked as well as incoming data?

Firewalls aren't so hard to understand.

Microsoft Vista and Microsoft XP Service Pack 2 come with firewalls that control incoming, but not outgoing data. Make sure that these firewalls are activated unless you decide to use another firewall program. Don’t ever have two or more firewalls active on a computer at the same time. They could easily interfere with each other leading to uncertain results.