It is easy to secure a computer system. You merely have to disconnect all dial-up connections and permit only direct-wired terminals, put the machine and its terminals in a shielded room, and post a guard at the door.
F.T. GRAMPP AND R.H MORRIS
Of course, very few people want to use such a host…
The Internet, like any other society, is plagued with the kind of jerks who enjoy the electronic equivalent of writing on other people's walls with spray paint, tearing their mailboxes off, or just sitting in the street blowing their car horns. Some people try to get real work done over the Internet, and others have sensitive or proprietary data they must protect. Usually, a firewall's purpose is to keep the jerks out of your network while still letting you get your job done. A firewall is a system or group of systems that enforces an access control policy between two networks. The actual means by which this is accomplished varies widely, but in principle, the firewall can be thought of as a pair of mechanisms:
one that exists to block traffic, and the other, which exists to permit traffic. As a firewalls serves this essential purpose of a gatekeeper it must be freely available to the users. Linux has a huge number of firewalls that are available freely. But most of the firewalls available for Windows are commercial ones.
These commercial firewalls charge a lot for their services. For instance,
- McAfee Firewall: Rs.1500
- Norton Antivirus: Rs.3000
- Zone Alarm: Rs.2500
- All the prices specified above are for a single copy of the software. Thus an organization would need many such copies. Therefore, even if an organization requires a low-cost alternative it would have no option but to go for the commercial firewalls.
- In India, because of the above-specified prices, software piracy is increasing. Due to the exorbitant pricing people have no option, but to use the pirated software that is available cheaply. This is unethical because then the software companies lose out on their revenue, which gradually affects the overall quality of the final software.
- Moreover, if you decide to develop a firewall for Linux, you will find a lot of information and source code, all free. However the people interested in designing firewall for Windows Platforms have difficulty not only while searching for information, but also while finding a open source code.