Firewall Basics

A firewall is a device that connects two or more networks together and restricts the flow of information between the two or more networks according to rules configured in a firewall rule base.

Firewalls have been in use for more than 20 years, but only in the past 10 years (because of the rapid growth of the Internet) has the need for firewalls increased, along with their capabilities.

In an ideal world, a firewall would not be required. You could just allow everybody full access to all your resources, and you could trust them to access what they required. However, in the real world, firewalls have become a necessity for all organizations to limit the access to their resources to users who require access to those resources. ...

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