Over the past decade, the explosion in the number of connected objects (IoT), the generalization of digital services and the digital transformation of economies have put increasing pressure on the IPv4 addressing system, originally designed for a much smaller Internet. Today, the global shortage of IPv4 addresses is a reality: the last blocks have been allocated by regional registries, creating tensions over the availability and efficiency of the global network. Faced with this situation, the Internet Engineering Task Force (IETF) designed a replacement protocol in the 1990s: IPv6, based on a 128-bit address space (compared with 32 bits for IPv4). This protocol can generate an almost unlimited number of IP addresses, paving the way for massive interconnection of objects, services and users. It is also designed to incorporate advanced features such as autoconfiguration, simplified routing and enhanced network security. Since the early 2000s, IPv6 has been progressively activated worldwide. However, the pace of deployment remains uneven across regions, sectors and operators. In recent years, stagnation, or even regression, has been observed in some areas, due to a double blockage: service providers are slow to adapt their offers due to a lack of IPv6 users, while operators are delaying their migration due to a lack of concrete customer usage. This vicious circle is holding back widespread adoption of IPv6. However, this dynamic is changing rapidly. The digital giants (Google, Apple, Facebook, Amazon, Microsoft, etc.) have fully integrated IPv6 into their infrastructures. What's more, the rise of emerging technologies such as 5G, IoT, distributed cloud and smart grids makes IPv6 adoption unavoidable.
In this context, migration to IPv6 is no longer a strategic choice, but a functional and economic necessity. It has become imperative to modernize networks (from core infrastructure to application services) to guarantee their durability, performance and security in a constantly evolving digital environment.
This document is an updated version of the «2019 practical guide to IPv6 migration». It aims to provide guidance to companies, operators, administrations and service providers in their transition from IPv4 to IPv6, taking into account local realities and international standards.
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