Broadband Guide

Firewalls - The Basics

Confused about firewalls? Like a lot of computer jargon, the term "firewall" refers to a surprisingly simple piece of kit, but it’s essential to understand what one is and how to get hold of one, especially if you’ve got a broadband connection.

What is a firewall?

A firewall is a computer programme that blocks the gateway between two networks - usually the private network of your computer and the public network of the internet. It blocks the channel to ensure that unwanted visitors from the internet can’t get into your private network. As a broadband connection is effectively open 24 hours a day (regardless of whether your computer is switched on), there’s a lot of time for someone to get into your personal files if they want to, but a firewall makes that almost impossible.

The firewall does this by filtering all the information that comes through your connection, as well as segmenting your network into different physical subnetworks, limiting the damage that can spread from one to the next. This is where the term comes from, as it works like a fire door or firewall in the real world.

Types of firewalls

You can get a firewall as a piece of software or hardware. As hardware, it’s usually part of a router which then connects to your home network. If you don’t need a router, you’re probably better off installing firewall software onto your main computer (any computer in your house that directly receives a broadband signal). Some firewall software is free to download, but some more advanced packages carry a charge.

Firewall software

Free firewall software:

Windows built-in firewall – Basic software
ZoneAlarm – Good software

Paid-for firewall software:

Norton Internet Security – Good, includes virus scan
McAfee Internet Security Suite – Good, includes virus scan
ZoneAlarm Internet Security Suite – More advanced
Panda Platinum Internet Security – Includes virus scan

The easiest way to get a hardware firewall is through your broadband router. Some routers have a built-in firewall (which you may have to enable yourself – your instruction manual should tell you how to do this), including:

Netgear
Belkin
Dlink
Hayes
LinkSys
BT Voyager
US Robotics.

Where can I buy a firewall?

Firewalls, whether software or hardware, are readily available now that more households are upgrading to broadband. Take a look at the listings above for information about where you can pick up the relevant equipment.