[Q] What is the purpose of a Firewall? What does it do?
[A] A Firewall is designed to restrict access to a network
by selectively allowing or blocking inbound traffic to the network.
It can also control abound traffic from a user or a program.
A
Firewall controls traffic by monitoring the various network
ports. A software network port is an identified doorway (address)
for communicating between a program and another communications
system or program often passing through a hardware port. The
network port is usually numbered and a standard network implementation
will attach a port number to data it sends. The receiving implementation
will guard and listen at the attached port number (doorway)
to figure out which program to send data to on its system. A
port may send/receive data one direction at a time (simplex)
or simultaneously in both directions (duplex). These software
network ports may also connect internal programs on a single
computer system.
If
are currently operating with a firewall, you most likely have
noticed that when you load certain programs on your computer,
or when you start certain programs, you receive a warning from
the Firewall software indicating an attempt by a program to
establish an outbound connection. Most legitimate programs can
be configured automatically by the Firewall to allow programs
up dates and other routine tasks.
Always
be careful when configuring your firewall, as it is possible
to accidentally block access to a required resource that may
cause a program to no longer work correctly. In some cases,
you can even disable your own internet access by placing too
many restrictions in your firewall settings.
Always
refer to a qualified technician or other reliable expert if
you are in doubt about whether you are making the right choice
regarding how much access you grant or deny a program.
Fire walls
are available as Hardware devices, or as software programs that
secure the communication lines that are already in place.
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Keywords: Firewall
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