IPv6 Upgradation - An Engineering Exercise or a Necessity?

IPv4 is the basis of the TCP/IP communication protocols which are used to transport data, voice and video packets over the Internet. It is well known that in today’s IPv4-based Internet, the relatively limited number of available addresses has encouraged the use of certain techniques and technologies, such as Network Address Translation (NAT) in particular. These technologies have compromised the ability of the network to diversify in terms of applications. The limited size of IPv4 address space imposes a strict limit on the ability of the network to grow substantially, for instance to two or three orders of magnitude larger than today’s Internet. If such growth were to occur using IPv4 address space, additional and substantial architectural compromise would be required, which would further reduce the simplicity, integrity and uniformity of the network. Due to recent concerns over the impending depletion of the current pool of Internet addresses and the desire to provide additional functionality for modern devices, an upgrade of the current version of the Internet Protocol (IP), called IPv4, has been defined. This new version, called IP version 6 (IPv6), resolves unanticipated IPv4 design issues and takes the Internet into the 21st Century. This paper describes the problems of the IPv4 Internet and how they are solved by IPv6, the new features introduced in the emerging Internet Protocol standard and why they have been introduced. IPv6 addressing, the new IPv6 header and its extensions, the IPv6 replacements for the Internet Control Message Protocol (ICMP) and Internet Group Management Protocol (IGMP), neighboring node interaction, and IPv6 address auto configuration. This paper provides a foundation of Internet standards-based IPv6 concepts and is intended for network engineers and support professionals who are already familiar with basic networking concepts and TCP/IP.