Chapter 1. IPv6 Versus IPv4

IPv6 is sometimes called the Next Generation Internet Protocol, or IPng. Even though the Internet is seen as a relatively new technology, the protocols and technologies that make it work were developed in the 1970s and 1980s. The current Internet and all our corporate and private intranets use IPv4. Now, with IPv6, the first major upgrade of the Internet protocol suite is on the horizon or maybe even closer. Close enough, anyway, to start taking it seriously.

The History of IPv6

The effort to develop a successor protocol to IPv4 was started in the early 1990s by the Internet Engineering Task Force (IETF). Several parallel efforts began simultaneously, all trying to solve the foreseen address space limitation as well as provide additional functionality. The IETF started the IPng area in 1993 to investigate the different proposals and to make recommendations for further procedures.

The IPng area directors of the IETF recommended the creation of IPv6 at the Toronto IETF meeting in 1994. Their recommendation is specified in RFC 1752, “The Recommendation for the IP Next Generation Protocol.” The Directors formed an Address Lifetime Expectation (ALE) working group, whose job was to determine whether the expected lifetime for IPv4 would allow the development of a protocol with new functionality or if the remaining time would only allow for developing an address space solution. In 1994, the ALE working group projected the IPv4 address exhaustion to occur sometime between 2005 and 2011, based on the statistics that were available at that time.

For those of you who are interested in the different proposals, here’s some more information about it (from RFC 1752). There were four main proposals called CNAT, IP Encaps, Nimrod, and Simple CLNP. Three more proposals followed: the P Internet Protocol (PIP), the Simple Internet Protocol (SIP), and TP/IX. After the March 1992 San Diego IETF meeting, Simple CLNP evolved into TCP and UDP with Bigger Addresses (TUBA) and IP Encaps evolved into IP Address Encapsulation (IPAE). IPAE merged with PIP and SIP and called itself Simple Internet Protocol Plus (SIPP). The TP/IX working group changed its name to Common Architecture for the Internet (CATNIP). The main proposals were now CATNIP, TUBA, and SIPP. For a short discussion of the proposals, refer to RFC 1752.

Tip

CATNIP is specified in RFC 1707, TUBA in RFC 1347, RFC 1526, and RFC 1561, and SIPP in RFC 1710.

The Internet Engineering Steering Group approved the IPv6 recommendation and drafted a Proposed Standard on November 17, 1994. The core set of IPv6 protocols became an IETF Draft Standard on August 10, 1998.

Tip

Why is the new protocol not IPv5? The version number 5 could not be used because it had been allocated to an experimental stream protocol.

Get IPv6 Essentials now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.