FIREWALLS

What Is A Firewall? A computer firewall protects networked computers from intentional hostile intrusion that could compromise confidentiality or results in data corruption or denial of service. It may be a hardware device or a software program running on a secure host computer. A network firewall sits at the junction point or gateway between two networks, usually a private network and a public network such as the Internet. The earliest computer firewall were routers.

How Firewalls Work A firewall is simply a program or hardware device that filters the information coming through the Internet connection into your private network or computer system. If an incoming packet of information is flagged by filters, it is not allowed through.

Software Firewall Such as ZoneAlarm, can be installed on the computer in your home that has an Internet connection. This computer is considered a gateway because it provides the only point of access between your network and the Internet.

Hardware Firewall With a hardware firewall, the firewall unit itself is normally the gateway. A good example is the Linksys Cable/DSL router. It has a built-in Ethernet card and hub. Computers in your home network connect to the router, which in turn is connected to either a cable or DSL modem. You can then set any filters or additional information.

Hardware Firewall…. …are incredibly secure and not very expensive. Home versions that include a router, firewall and Ethernet hub for broadband connections can be found for well under $100.

Remote Login Application Backdoors SMTP Session Hijacking Operating System Bugs Denial of Service Bombs Macros Viruses Spam Redirect Bombs Source Routing What It Protects You From

Access Denial Methodologies used by Computer Firewalls: A firewall may allow all traffic through unless it meets certain criteria. –Type of traffic –Source or Destination addresses and ports or It may deny all traffic unless it meets certain criteria

FIREWALLS Everything You Wanted To Know About Firewalls