IPv6

IPv6
Name	IPv6
Developer	Internet Engineering Task Force
Introduction	December 1998
Based on	IPv4
Osi layer	Internet layer

IPv6. Internet Protocol version 6 is the most recent version of the Internet Protocol, the communications protocol that provides an identification and location system for computers on networks and routes traffic across the Internet. It was developed by the Internet Engineering Task Force to deal with the long-anticipated problem of IPv4 address exhaustion, and is intended to replace IPv4. The new protocol offers a vastly expanded address space, improved packet handling, and integrated security features, forming the foundation for the next generation of internet connectivity.

Introduction

The development of this protocol was driven by the imminent exhaustion of addresses within the IPv4 addressing system, a limitation recognized as early as the 1990s. The Internet Engineering Task Force initiated the design process, which culminated in the publication of the core standards in 1998. Key figures and organizations involved in its creation and promotion include Vint Cerf, often called a "father of the Internet," and the Internet Society. Its deployment is considered critical for supporting the exponential growth of connected devices, from smartphones to sensors in the Internet of Things, ensuring the continued expansion of the global internet infrastructure.

Technical specifications

The protocol operates at the Internet layer of the TCP/IP model, defining how packets are sent and received. A fundamental change from its predecessor is the use of a 128-bit address, compared to the 32-bit address used in IPv4, which astronomically increases the number of available unique addresses. The header format was simplified to improve processing efficiency by routers, with fields like the Header Checksum removed. Other significant technical enhancements include improved support for extensions and options through an efficient Extension Header mechanism, and refined methods for Packet fragmentation handled primarily by the source device rather than network routers.

Addressing

The 128-bit address space is typically represented in hexadecimal notation, divided into eight groups of four hexadecimal digits, separated by colons, such as in addresses used by Google or Facebook for their services. Addresses are hierarchically allocated by the Internet Assigned Numbers Authority to regional internet registries like the American Registry for Internet Numbers and the Réseaux IP Européens Network Coordination Centre, who then assign blocks to Internet service providers. Unicast, multicast, and anycast types are defined, with a specific block reserved for unique local addresses analogous to private addresses in IPv4. The Neighbor Discovery Protocol operates using multicast to manage the interaction between nodes on the same link, replacing the Address Resolution Protocol used in the older standard.

Transition mechanisms

Due to the need for coexistence with the extensive installed base of IPv4, several transition technologies have been standardized. Dual-stack operation, where network devices run both protocols simultaneously, is a fundamental strategy. Tunneling techniques, such as 6in4 and Teredo tunneling, encapsulate packets within IPv4 packets to traverse legacy network segments. Translation mechanisms, including Network Address Translation-Protocol Translation and carrier-grade technologies, allow for communication between pure hosts and those only using the older protocol. Large-scale deployment efforts by companies like Microsoft and Comcast have relied on these mechanisms to facilitate a gradual migration.

Security features

A major architectural improvement is the mandatory implementation of IPsec, a suite of protocols for securing internet protocol communications by authenticating and encrypting each packet, which was originally developed for the older protocol but is now integral. While not always automatically used, its availability provides a foundation for secure end-to-end communication. The new protocol also includes protections against specific types of attacks; for instance, the redesign of the Neighbor Discovery Protocol includes safeguards against spoofing and redirection attacks that were possible in the older Address Resolution Protocol. These features enhance the overall security posture of the Internet as adoption increases.

Deployment and adoption

Global adoption has been a gradual process, accelerating in the 2010s as regional internet registries exhausted their pools of IPv4 addresses. Major content providers like Google, Facebook, and Netflix have enabled access to their services, while telecommunications giants such as Verizon Wireless and AT&T have deployed it across mobile and fixed networks. Significant milestones were reached during events like the World IPv6 Launch in 2012, coordinated by the Internet Society. As of recent years, a substantial percentage of traffic to major networks like Google and the Akamai Technologies content delivery network now uses the new protocol, indicating its steady progression toward becoming the dominant internet protocol.

Category:Internet protocols Category:Internet standards