IPv6 — The History and Timeline
by Kaushik Das


The current version of the Internet Protocol IPv4 was first developed in the 1970s, and the main protocol standard RFC 791 that governs IPv4 functionality was published in 1981.

With the unprecedented expansion of Internet usage in recent years — especially by population dense countries like India and China.

The impending shortage of address space (availability) was recognized by 1992 as a serious limiting factor to the continued usage of the Internet run on IPv4.
With admirable foresight, the Internet Engineering Task Force (IETF) initiated as early as in 1994, the design and development of a suite of protocols and standards now known as Internet Protocol Version 6 (IPv6), as a worthy tool to phase out and supplant IPv4 over the coming years. There is an explosion of sorts in the number and range of IP capable devices that are being released in the market and the usage of these by an increasingly tech savvy global population. The new protocol aims to effectively support the ever-expanding Internet usage and functionality, and also address security concerns.

IPv6 uses a128-bit address size compared with the 32-bit system used in IPv4 and will allow for as many as 3.4×1038 possible addresses, enough to cover every inhabitant on planet earth several times over. The 128-bit system also provides for multiple levels of hierarchy and flexibility in hierarchical addressing and routing, a feature that is found wanting on the IPv4-based Internet.

A brief recap of the major events in the development of the new protocol is given below:
— Basic protocol (RFC 2460) published in 1998
— Basic socket API (RFC 2553) and DHCPv6 (RFC 3315) published in 2003.
— Mobile IPv6 (RFC 3775) published in 2004
— Flow label specifications (RFC 3697) added 2004
— Address architecture (RFC 4291) stable, minor revision in 2006
— Node requirements (RFC 4294) published 2006

IPv6 Features

The massive proliferation of devices, need for newer and more demanding applications on a global level and the increasing role of networks in the way business is conducted are some of the pressing issues the IPv6 protocol seeks to cater to. The following are the features of the IPv6 protocol:
— New header format designed to keep header overhead to a minimum — achieved by moving both non-essential fields and optional fields to extension headers that are placed after the IPv6 header. The streamlined IPv6 header is more efficiently processed at intermediate routers.
— Large address space — IPv6 has 128-bit (16-byte) source and destination IP addresses. The large address space of IPv6 has been designed to allow for multiple levels of subnetting and address allocation from the Internet backbone to the individual subnets within an organization. Obviates the need for address-conservation techniques such as the deployment of NATs.
— Efficient and hierarchical addressing and routing infrastructure- based on the common occurrence of multiple levels of Internet service providers.
— Stateless and stateful address configuration both in the absence or presence of a DHCP server. Hosts on a link automatically configure themselves with link-local addresses and communicate without manual configuration.
— Built-in security: Compliance with IPSec is mandatory in IPv6, and IPSec is actually a part of the IPv6 protocol. IPv6 provides header extensions that ease the implementation of encryption, authentication, and Virtual Private Networks (VPNs).