Chapter 5. Overview of Security Technologies

“We can’t help everyone, but everyone can help someone.”

—Ronald Reagan

This chapter discusses the use of technologies that have evolved to support and enhance network security. Many of these technologies are used today without the user understanding when or where they operate. After reading this chapter, you will understand the benefits of these technologies, where they operate, and some of the operational risks associated with them. By the end of this chapter, you should know and be able to explain the following:

• How you can employ packet filtering to reduce threats to a network

• Understand precisely what stateful packet inspection is, and why its important for firewalls to use this technique

• The role and placement of a proxy technology within a secure network

• Network Address Translation (NAT) and how you can use it to allow the Internet to continue to grow in IPv4

• How Public Key Infrastructure (PKI) has the potential to protect the flow of information in a global manner

Answering these key questions and understand the concepts behind them will enable you to understand the overall characteristics and importance of the security technologies covered in this chapter. By the time you finish this book, you will have a solid appreciation for network security, its issues, how it works, and why it is important.

So far, this book has painted in broad strokes the steps an attacker could possibly take to gain access to sensitive resources. The first step in protecting these assets is the global security policy created by combining the many aspects discussed in Chapter 2, “Security Policies.” This chapter introduces some of the more broadly used security technologies. Each of these technologies contains a concept or specific role that increases the security of your network when designed and implemented in a layered design.