3 - Patching IPv4

Abstract

This chapter examines four basic strategies that have been used to allow IPv4 to cope with its unprecedented growth and then look at the way those strategies have been implemented. For the IETF, patching IPv4 has been a priority, alongside the priority of developing a successor protocol, since the early 1990s. The efforts to extend IPv4's useful life may have been too successful, having pushed the imminent demise of the IPv4 addressing space from 1994 to as far out as 2011 or even further. A variety of strategies, including conservation, rationing, and replacement, have been used over the years, and for many network experts these efforts have succeeded far beyond their goals of stopgap, short-term, solutions. The chapter introduces the most important responses to the IPv4 address space shortage made by the Internet community. The true cost of IPv6-enabling any particular server, host, router, or network is difficult if not impossible to calculate. However, experts have predicted that enterprises can anticipate price tags for the task to be as much as 10 times greater than the cost of their Y2K preparations.