Functions of Firewalls

In a security defense system, firewalls are usually the first line of defense against most of the external attacks.

In practical applications, since a single security defense technology cannot construct a network security system, multiple technologies should be used together to minimize security risks. In general, the first step to implement security defense is to construct a barrier, known as a firewall, between intranets and the Internet to protect intranets agains the attacks from the Internet.

Firewalls are mainly used for the following purposes:

• Restricting the entry of users or information from a specific and strictly-controlled Website.

• Preventing attackers from accessing other security defense facilities.

• Restricting the exit of users or information from a specific and strictly-controlled website.