A retrospective view of network address translation

Today, network address translators, or NATs, are everywhere. Their ubiquitous adoption was not promoted by design or planning but by the continued growth of the Internet, which places an ever-increasing demand not only on IP address space but also on other functional requirements that network address translation is perceived to facilitate. This article presents a personal perspective on the history of NATs, their pros and cons in a retrospective light, and the lessons we can learn from the NAT experience.