Application layer firewalls have been a popular tool for security practitioners since the early 1990’s. Today, they are considered a mandatory component of any industry or government network. Unfortunately, many consumers of these fundamental networking tools buy and rely on them without understanding that there can be dramatic differences between firewalls that are manufactured by competing security practitioners and their unique engineering teams.

This paper describes the evolution of firewalls from the standpoint of the controls that they apply on data, and explains why the currently accepted "state-of-the-art" application layer firewall really represents a step backwards in most cases for securing perimeters.

Download this paper and learn more about Application Layer Firewalls.