CHAPTER Network Address Translation 27 What You Will Learn In this chapter, you will learn how NAT (originally used to address the shortage of IPv4 addresses) is now used to conceal public IPv4 addresses. We'll talk about the advantages and disadvantages of using NAT for this purpose. You will learn that there are four types of NAT and find that using NAT for secu- rity is not the best use of NAT. We'll also configure the popular NATP and see how