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The TCP/IP Guide  9  TCP/IP Lower-Layer (Interface, Internet and Transport) Protocols (OSI Layers 2, 3 and 4)       9  TCP/IP Internet Layer (OSI Network Layer) Protocols            9  Internet Protocol (IP/IPv4, IPng/IPv6) and IP-Related Protocols (IP NAT, IPSec, Mobile IP)                 9  Internet Protocol Version 6 (IPv6) / IP Next Generation (IPng)

Internet Protocol Version 6 (IPv6) / IP Next Generation (IPng) 1 IPv6 Motivation and Overview

IPv6 is destined to be the future of the Internet Protocol, and due to IP's critical importance, it will form the basis for the future of TCP/IP and the Internet as well. In fact, it's been under development since the middle of the last decade, and a real IPv6 internetwork has been used for testing for a number of years as well. Despite this, many people don't know much about IPv6, other than it's a newer version of IP. Some have never even heard of it at all! We're going to rectify that, of course—but before we delve into the important changes made in version 6 to how IP addressing, packaging, fragmentation and other functions, let's start with a “bird's eye” view of IPv6.

In this section I provide a brief higher-level overview of IPv6, including a look at how it differs from IPv4 in general terms. I begin with a brief overview of IPv6 and why it was created. I list the major changes made in IPv6 and additions to the protocol from the current version. I also explain some of the difficulties associated with transitioning the enormous global Internet from IPv4 to IPv6.

Internet Protocol Version 6 (IPv6) / IP Next Generation (IPng) 1 IPv6 Motivation and Overview