Chapter 2 - Protecting your perimeter

Abstract

This chapter focuses on securing the network perimeter. With the current trend of security breaches originating from the inside of the network (often employees or ex-employees), companies are increasingly relying on firewalls to isolate and filter traffic between portions of the internal network. The chapter reviews some basic firewall concepts and briefly discusses the different architectural ways to implement a firewall. Most of the chapter discusses the installation and configuration of free firewalls to run on both Windows- and Linux-based systems. Within the realm of firewalls there are many different ways to restrict network traffic. Most of these methods vary in the level of intelligence that is applied to the decision-making process. The most securely configured firewall in existence will not provide much protection if a network was not designed properly. Finally, the chapter discusses ways of creating controlled, secure paths through the perimeter for remote connectivity, including administrative access or remote office/work from home scenarios.