Firewall- An Overview

By Author: Kay Johnson
Total Articles: 117
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The term Firewall means a wall to protect the house from fire. Firewall technology was introduced in 1980s, when the Internet was a novel concept in terms of global usage and connectivity. Before firewalls, routers were used for network security for separation of networks from each other.

A Firewall is an application that is present in the computer to inspect the network traffic. It is usually sited in-between a well-protected network and an undefended network. It acts as if it is a gate, which gives protection to the assets and makes sure nothing private goes out and nothing nasty comes in. Basically, Firewall regulates some of the flow of traffic in-between the computer networks where one cannot trust. A Firewall is also integral part of today's computer or the network that is specially designed to obstruct unlawful and illegal access and permitting the authorized communication. It is a tool or an appliance or a set of appliances configured to allow or to deny the computer applications with reference to the set of rules and other criteria.

Firewalls can be installed in either the hardware or software ...
... or its combination of these both. They are always used to block unauthorized users of internet from accessing private networks linked through Internet e.g. Intranet.. All the information, data, entering, or going out, passes through this Firewall. It checks every message and does not allow passing the one that does not meet the specified criteria.

There are different types of firewall available in the market, with different techniques. The packet filters technique- It is the technique that inspects each and every packet that passes through the network. It accepts or allows or rejects the packet based on the user-defined rules. Though, it is not easy and very difficult to configure, it is highly effective and highly transparent for the users. It is exposed to IP Spoofing.

The Application gateway- It is the technique that provides security mechanisms for certain applications, like the FTP and the Telnet servers. It is highly efficient, but one thing that needs to be taken into consideration is that it imposes performance degradation.

The Circuit-level gateway- It is the application, which implies security mechanisms when there is establishment of connectivity of TCP or UDP. At once, if there is connectivity been made, then the packets flows in-between the hosts and the flow of traffic are not further checked.

The Proxy server- It is a kind of technique, which interrupts all messages coming in and going out of the network. The advantage of this is that the proxy server with high effectiveness does not display the true network addresses. It hides the identity of the user, so others cannot misuse it.

The firewall determines if that traffic should continue on to its target or be stopped. The firewall "guard" is important because it keeps the unwanted out and permits only appropriate traffic to enter and leave the computer. To know more about computer security and related issues, visit savemysystem.co.uk. It is the best option for al the computer users that offers reliable services.
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