Different firewall techniques: A survey

Firewalls today are an integrated part of security mechanism of any organization or institution. Firewalls throughout the years have evolved merely from static rule mapping to understanding the dynamic behavior of traffic and react accordingly. Different firewall techniques operating in several layers of the TCP/IP model have been proposed by different authors in different times. In this paper an insight into some of the firewall techniques are discussed and also an attempt has been made to portray different challenges that exist in the application traffic.