Texas A&M International University
Network security tools must be developed and improved rapidly to defend against increasingly sophisticated and determined attackers. This paper examines the rationale and methodology behind \"Defense in depth\" network security systems, the design and functioning of these systems, and provides examples of network security tools that can be configured and used. It also contains information on network security tools, their classifications (e.g. traffic analysis, vulnerability assessment, etc.) from a review of the literature. These details freely available network security tools and how they can be used to improve network security.