Special Edition Using TCP/IP, Second Edition

Network Address Translation

Although VPNs offer an effective security mechanism for private internetworks, the cost of running separate application gateways for software installed on the computers in a private intertnetwork was too high. Therefore, an alternative security mechanism, called the Network Address Translation (NAT), was developed. NAT offers an encapsulation of an arbitrary number of computers and applications running on local computers. Although security is one of the major gains, NAT primarily attempted to solve the problem of lack of addresses in the IPv4 address space. As the need for security for information stored and transacted on private internetworks gained importance, the security features provided by NAT was found ...