Firewalls – What They Are And What They Do

Firewalls – What They Are And What They Do


A firewall is a system of protection for your computer which can be implemented in either hardware or software forms. The purpose of a firewall is to prevent unauthorized access to your computer or network.

A good firewall will offer you severa layers of system protection by applying various rules to the data coming to or leaving your computer. Whether or not your firewall is hardware or software or even a combination of both it should offer the following features:

Data Scanning
This feature checks all incoming data arriving to your PC and based on a set of rules either accepts the data or rejects it. This data is often referred to as packets.

Application Protection
This means that any program attempting to access the Internet for whatever reason must first be approved by you. Once you’ve approved the application to access the Internet once you don’t need to do so again.

TCP/UDP Port Scanning
Spyware is often used to deliver viruses directly to your PC. These various viruses will attempt to attack your computer via UDP (User Datagram Protocol) or TCP (Transmission Control Protocol) attacks. A standard TCP/IP connection to the Internet can leave a wide variety of ports open on your computer. Even a cheap firewall should always check that sensitive ports are blocked, all new ports being opened need to be authorized by you and also explain to you why the port is being accessed.

So how important is it to use a firewall? Absolutely essential!. Regardless of whether you use dialup, DSL, Cable or a company LAN connection not using a firewall is simply asking for trouble. If you don’t have a firewall on your PC then get one now – there’s a 99% chance that your computer has at least one virus or spyware issue right now if you’re not using firewall protection.

There’s a wide variety of firewalls available on the market today but one of the easiest to use is Zonealarm and it’s free! It does what it says on the tin and it does it well.

Whatever firewall you choose to purchase just make sure you purchase one. Much better that you have some protection against Internet threats than none at all.

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