Internet Protocol version 6 (IPv6) is the next generation of the Internet Protocol (IP). It was developed to enhance the capability of IPv4 by providing a vastly increased IP address space, to provide header space to meet security and other requirements, and to provide additional capability enhancements. The additional address space is needed to support expected large increases in the number of networked devices due to Internet growth, sensors and sensor nets, and mobile network devices. IPv6 supports 2128 (about 340 undecillion (340 x 1036)) IP addresses.
In addition, IPv6 was designed with the following goals: increased ease of network management and configuration, expandable IP headers, improved mobility and security, and quality of service controls.
The Internet Engineering Task Force (IETF) began work on IPv6 out of concern that the Internet would eventually run out of unique addresses. Originally published in 1981, IPv4 was designed to link a small number of research networks. IPv4 only allows addresses up to 12 digits, or about 4 billion unique addresses. IPv6 will provide the Internet with one billion-squared addresses, which should suffice for many years.
The U.S. Office of Management and Budget (OMB) mandated that government agencies incorporate IPv6 capability into their backbones (routers, gateways, etc.) by 2008. However, IPv6 was not launched until 2011.