Why a Firewall?

In most cases, the purpose of the firewall is to prevent unauthorized users from accessing
computing resources on a private network, and often to prevent unnoticed and unauthorized export of proprietary information. In some cases export of information is not considered important, but for many corporations that are connecting this is a major though possibly unreasoning concern. Many organizations will want simply to address the problem by not connecting to the Internet at all.

This solution can be difficult to implement. If the private network is loosely administered or decentralized, a single enterprising individual with a high speed dialup modem can quickly effect an Internet SLIP connection which can compromise the security of an entire network. Often it is safe to say that a firewall needs to be put in place for the "CYA"1 factor. Even though an employee could compromise proprietary information by carrying it offsite on a DAT or floppy disk, the Internet represents a tangible threat, populated with dangerous "vandals."2 It could very easily cost a network manager his job if a break-in occurs via this route, even if the damage is no more extensive than could have been inflicted over a dialup line or by a disgruntled employee. Generally, for a would-be Internet site, the technical difficulties of implementing a firewall are greatly outweighed by the public relations problems of "selling" upper management on the idea. In summary, because Internet services are so highly visible, they are much more likely to require official oversight and justification.

Light propelsion Courtesy Tintu Prinkle