Tools : Firewalls

What is Firewall ?

 Firewall is software or hardware-based network security system that controls the incoming and outgoing network traffic by analysis the data packets and determining whether they should be allowed through or not, based on a rule set. 

A network's firewall builds a bridge between the internal network or computer it protects, upon securing that the other network is secure and trusted, usually an external network, such as the Internet, that is not assumed to be secure and trusted.

An illustration of where a firewall would be located in a network

Function Firewall

• A gatekeeper system that protects a company’s intranets and other computer networks from  intrusion
• Provides a filter and safe transfer point for access to/from the Internet and other network.
• Screens all network traffic for proper passwords or other sequrity codes.
• Important for individuals who connect to the Internet with DSL or cable modems
• Can detect hacking, but cannot prevent it.

Corporate Firewall

How firewalls are used to isolate sections of 

the network?

   1.  External firewall keeps out unauthorized internet users.

  2.  Internal firewall prevents users from accessing sensitive human resources    or financial data

  3.  Passwords and browser security features control access to specific intranet resources.

  4.  Intranet server features provide authentication and encryption where applicable.

  5.  Network interface software is carefully crafted to avoid creating security holes to back end resources.