08 Mar 2008 12:28:38 | 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 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.