What is Firewall?

Broadly speaking, a computer firewall is a software program that prevents unauthorized access to or from a private network. Firewalls are tools that can be used to enhance the security of computers connected to a network, such as LAN or the Internet. They are an integral part of a comprehensive security framework for your network.

A firewall absolutely isolates your computer from the Internet using a "wall of code" that inspects each individual "packet" of data as it arrives at either side of the firewall — inbound to or outbound from your computer — to determine whether it should be allowed to pass or be blocked.

Firewalls have the ability to further enhance security by enabling granular control over what types of system functions and processes have access to networking resources. These firewalls can use various types of signatures and host conditions to allow or deny traffic. Although they sound complex, firewalls are relatively easy to install, setup and operate.

Most people think that a firewall is a of device that is installed on the network, and it controls the traffic that passes through the network segment.

However, you can have a host-based firewalls. This can be executed on the systems themselves, such as with ICF (Internet Connection Firewall). Basically, the work of both the firewalls is the same: to stop intrusion and provide a strong method of access control policy. In simple definition, firewalls are nothing but a system that safeguards your computer; access control policy enforcement points.

What Firewalls Do?

Basically, firewalls need to be able to perform the following tasks:

Defend resources




Validate access




Manage and control network traffic




Record and report on events




Act as an intermediary

What is Personal Firewall

It is important to understand why we need a firewall and how it helps us in the world of secure computing. We need to understand the goals of information security because it helps us to understand how a firewall may address those needs.

Why you need Personal Firewall

In the age of high-speed Internet Access, you electronically connect your computer to a broad network over which, unless you have installed a personal firewall, you have limited control and from which you have limited protection. Until recently, unless you worked for an organization that provided high-speed internet access.

Like anything, the high-speed connection has its own drawbacks. Ironically, the very feature that makes a high-speed connection attractive is also the reason that makes it vulnerable. In a way, connecting to the internet via high-speed connection is like leaving the front door of your house open and unlocked. This is because high-speed Internet connections have the following features:

• A constant IP - Make it easy for an intruder who has discovered your computer on the internet to find you again and again.
• High-Speed Access - Means that the intruder can work much faster when trying to break into your computer.
• Always active connection - means that your computer is vulnerable every time when it is connected to the internet.

Defending yourself with a Personal Firewall

So now you have an idea of how you are vulnerable every time when you are online on a high-speed Internet connection, compared to an ordinary 56Kbps connection. What you now need to know is how you can defend yourself against the threat posed by this type of connection

A Personal firewall is important when

• You surf the internet at home using an 'always on' broadband connection
• You connect to the internet via a public WiFi network in a park, cafe or airport
• You run a home network which needs to be kept isolated from the internet
• You wish to be kept informed when any program on your computer attempts to connect to the internet
• Most Personal Firewalls are highly configurable so you can easily create security policies to suit your individual needs