Software Firewall- types and utilities

Software firewall is a component of a computer network that is designed to block unauthorized access while allowing authorized communications. It is equipment configured to permit or deny network transmissions base on certain conditions.
Firewalls could be implemented in hardware or software or in a combination of both.

Different types of firewalls exist today which are mentioned below.

Packet filter: Packet filter verifies each packet transmitted through network and accepts or dumps it based on a user defined rules.

Application gateway: Application gateways deploy security mechanisms to specific applications. Though effective but causes performance degradation.

Circuit level gateway: Circuit level gateway uses security mechanisms when TCP or UDP transmissions take place.

Proxy server: Proxy servers inspect all message packets entering or leaving network. It conceals the true network addresses.

Software firewall could be very effective in computer security by preventing viruses from entering the system. It could prevent the unwanted and junk data from getting disseminated. It could protect the data integrity of the computer system. The firewall could identify the source of the junk data and bar the information transmitted from that source.