The Age of IPv6

Abstract

1.1 INTRODUCTION The current internet protocol, IP version 4 or shortly IPv4 was born to interconnect educational and government institutions in United States. Thus, the original IP protocol is naturally light and simple. Since the IPv4 based Internet is widely used throughout the world, current status of IPv4 is beyond imagination of the initial motivation to create it. As IP protocol is applied to the bigger network, internet engineers have realized that the original features of IP protocol are not enough. This becomes getting worse when IP protocol is adopted to open public networks. For the commercial network service, IP protocol needs more features to satisfy user demands for a better service. Since IP protocol was defined in Request for Comments (RFC) 791 in 1981, a lot of extensions and additional protocols have been added, such as path Maximum Transmission Unit (MTU) discovery, super-netting, Address Resolution Protocol (ARP), Dynamic Host Configuration Protocol (DHCP), Network Address Translation (NAT), etc. whenever necessity arises. These extensions as well as additional protocols are defined in separate documents by Internet Engineering Task Force (IETF). 1 1 The IETF is a large open international community of network designers, operators, vendors, and researchers related to the evolution of the Internet architecture and the smooth operation of the Internet. 2 The Age of IPv6 However, cooperating with new extensions and additional protocols may not be appropriate any more due to the huge overhead for compatibility with existing protocols. In other words, simple and light IPv4 protocol working with lots of additional protocols becomes very complicated to be implemented and operated properly on various devices in Internet. Even worse, Internet users have increased by the geometric progression every year, which incurs shortage in address resources. IPv4 uses 32-bit identifier so that there are 4.3 billion identifiers numerically, but address allocation based on classes allows only 0.5 or 1 billion address space. CIDR 2