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→Understanding Firewalls
== Understanding Firewalls ==
Much like a firewall in real life protects parts of a buildings from a spreading fire, an IT firewall protects computer systems from the dangers posed by an internet connection. A firewall is essentially a component located between a computer or a network of computers and the internet. The specific purpose of a firewall is to prevent unauthorized access to the computer systems it is configured to protect. Firewalls take the form of software, hardware or a combination of both and are not limited to use by large companies. Any one who owns a computer (including home users) that is connected to the internet for even short periods of time should have a firewall configured.
A good security strategy should consist of multiple layers of protection and in such a scenario, the firewall is typically the first line of defense.
Firewalls fall into three main categories - ''Packet-filtering'', ''Proxy-service'' and ''Stateful-inspection'' firewalls, each of which will be covered in detail here.
== Packet-Filtering Firewalls ==