What is a Firewall:
Firewalls protect you from being hacked or exploited. It is
an application program that protects you from intruders. It inspects each
incoming packet to allow only safe data to traffic. A great example of the
need for firewall is the recent onslaught of MS Blaster virus which spread
by exploiting a vulnerability. This worm spread to a PC just by exploiting
a vulnerability and using the TCP port to infect. The moment you connect
to the internet your machine could get infected by this worm.
Firewalls also let you control what programs can connect to
the Internet from your machine and what programs could connect to you from
the internet allowing complete control over what is going on in your PC.
Especially requiring this kind of protection are machines which are
permanently connected to the Internet using links like DSL (Digital
Subscriber Line). When you connect to the Internet using these type
of connections you are likely to be with a TCP/IP address for a longer
period of time unlike PCs which dial-up and connect to the ISP (Internet
Service Provider).
Not only for Hacking: Firewalls are often described
as solutions to hacking. This is since they block TCP/IP protocol and
render most TCP ports inaccessoble. However today due to other threats
like worm which can infect a machine directly through a TCP/IP port its
applications have widened.
How to Setup or Activate:
In windows XP which is our primary OS under discussion in this
guide, Service PAck1 and 2 versions provide firewalls. In service Pack 2
firewall functionaly is more feature rich. Firearll in windows XP can be
enabled from control panel security center in Service PAck2 and from
with networking in service pack 1.
Minor Inconveniences: One downside of
installing firewalls are some of the legitimate programs that you would
like to use, like Messengers or PC to PC phone call programs could stop
working due to blocking of the TCP ports required for them to work.
These are small nuisances and with the latest firewalls any program can
be easily unblocked.
