PC Doctor+ Guide 2 Firewalls

Written By: Steve Latimer

Get Some Protection: Part 2 Firewalls

First there were viruses and now there are Firewalls – confusing isn’t it?

The ability of computers to talk to each other and exchange files is one of their great advantages. This ability is what lies behind the Internet.

Sadly, there are always people out there ready to spoil the party by abusing this ability. These are the people with malicious intent and those who see this access to your computer as a commercial opportunity. Controlling who can access your computer has therefore become a major concern and Firewalls provide us with the answer.

The only question you need to ask is how you go about it

What Is A Firewall?

You can think of a Firewall as a Policeman checking the traffic between your own computer and the other computers that make up the network to which you are connected. This network can be an internal network e.g. in your place of work, or the millions of computers that make up the Internet.

How Does it Work?

Every computer on a network has its own IP address and in theory can connect to any other computer on the network. This allows other users with the appropriate software to transfer files to and from computers on the network. Of course this ability has many advantages and is the basis of millions of computer networks worldwide.

It’s not quite as simple as this as computers have to conform to certain protocols before being able to communicate with each other and the Internet itself incorporates security features which help to prevent certain access.
Nevertheless, the potential for unauthorised access to your computer by others remains high.

Firewalls have in built libraries of dodgy IP addresses and can be ‘trained’ to recognise friendly and unfriendly computers. Some firewalls, such as ‘Zone Alarm’ will alert you when another computer is trying to access yours and allow you to decide whether or not to let the access go ahead. Programs such as Internet Explorer and Outlook obviously require Internet access in order to complete their tasks and so you would say YES to the appropriate alerts. Your replies can be remembered by Zone Alarm and the list of friendly and unfriendly programs and computers consequently grow.

Windows XP comes with it’s own Firewall which you can access by right-clicking on the appropriate connection icon and selecting PROPERTIES. It is active by default. For those using other versions of Windows ARRIVAL recommends using Zone Alarm. There are both free and Pro versions of Zone Alarm.

You can download the free version of Zone Alarm from the Arrival Web Site at www.arrival-computers.co.uk.

Installation is straight forward if you accept all of the defaults suggested by the program. A re-boot will be necessary to make the program fully active. We would strongly urge you to take the time to work through the in-built tutorial in order to get the most out of the software.

Leave the ALERTS setting turned on for a couple of day as it’s both interesting and alarming to see the number of instances when an outside computer will try to access your own. Normally the user is oblivious to such instances. You can turn off the alerts once they begin to become distracting.

About the Author

Steve Latimer is Systems Manager at Arrival Computers. ( http://www.arrival-computers.co.uk )The PC Doctor+ Guides are aimed at users relatively new to computing. There are no objections to readers using the guides as content on their own web sites although a link back to the Arrival Site is always appreciated.

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