Firewall

A firewall is usually defined as a program with a predetermined set of rules that protects a computer system from potential damage caused by accessing websites that could be sources of damage.

Firewalls usually exist wherever there are two or more networks connected to each other via an intranet or the internet. Firewalls may also be used by network administrators to block certain websites which they believe should not be accessed from a company-owned computer by employees.

While most operating systems come with built in firewalls, it is also advisable for users to opt for independent firewalls or antivirus programs with built in firewalls to enhance the safety of their systems.

Firewalls usually work on the basis of established trust among networks or within a particular network. If a network contains several systems or has an intranet in place, the intranet or network system is likely to be a more trusted channel than a public access system such as the internet.

What many users do not realize is that a firewall is not in itself an antivirus program. Like a concrete firewall which is installed in a building to prevent damage in the event of a fire on the premises from spreading to other areas of the building, a firewall in its basic mode can only prevent damage from spreading.

In addition, it should also be kept in mind that a firewall is practically useless unless it is specifically configured to receive new updates and to routinely check for instructions on trustworthy areas in the network or on the internet.

The fact that firewalls were originally developed merely to keep networks separate from one another should give an indication of the amount of protection that they may be able to provide in the event of a virus attack.

Most present generation firewalls can at the most monitor the traffic generated through the ‘compartments’ in the networks that they perform within, and even such monitoring is limited by the amount of attention that is given to updating the firewall and keeping it accurately configured. Advanced firewalls can filter traffic on the basis of elements such as IP addresses and online ports as well.

Proxy servers can also act as firewalls since they make it more difficult for hackers to access a system or website from an external position. However, proxy servers have also led to some phishing concerns since it is easier for a spammer or malignant source to ‘hijack’ a proxy server and make it appear to be the actual website.

In such a case, particularly on commercial websites, unwary users tend to run the risk of exposing their financial information to the phishing expert while believing that they are on the authentic website.

Both proxy servers and other kinds of firewalls are now becoming increasingly popular with individual users as well as those with access control over networks.

However, learning how to configure a firewall for maximum benefit is still less user-friendly than most antivirus programs, and is not likely to become accessible to the lay user in the near future.