Recognizing that the 32-bit addresses used by the current version of the Internet Protocol (IPv4) would soon be depleted, the Internet Engineering Task Force (IETF) has been developing its successor, Internet Protocol version 6 (IPv6). This has been a more complex undertaking than simply changing implementations to accommodate larger addresses. In addition to the basic features (types of addresses, their allocation and management; routing; header format; etc), several classes of enhancements have been defined: a streamlined IP header, extensibility to future protocols, security, mobility, quality of service (QoS), and autoconfiguration. Meanwhile, interim solutions (CIDR and NAT) have been deployed to slow down the IPv4 address depletion, and several of the advances that were supposed to distinguish IPv6 were retrofitted so that they could be used within IPv4. IPv6 adoption is challenging, since there are numerous moving targets: IPv6-related protocol standards, implementations, and new technological advances and applications. IPv4 and IPv6 are expected to be deployed concurrently in the Internet for the foreseeable future. The US Government and DoD are planning an early, phased adoption of IPv6. NIST has developed an IPv6 Profile for the Federal Government and is working with DoD to create a unified set of requirements. This article provides the rationale for the US Government's edict, and describes the technical features that distinguish IPv6 from its predecessor IPv4 protocol.
IEEE Security & Privacy
Internet standards, Internet Protocol Version 6, IPv6