What is it?
Internet Protocol version 6 (IPv6) is a network layer protocol for packet-switched networks. It is designated as the successor to IPv4, the current version of IP, for general use on the internet. It is being included in all new mainstream operating systems, including Windows Vista.
Approaches to IPv6 vary around the world. The US Department of Defense wants its contractors and itself to support IPv6 by 2008. The US government has bought 247 billion IPv6 addresses, and Bechtel and Lockheed Martin are both implementing IPv6. China is in the middle of a five-year migration, and other Asia-Pacific countries are giving it priority.
But the European Union has done little more than fund task forces, and the UK government's policy is "for a gradual migration to IPv6, maintaining co-existence with IPv4 and to procure dual IPv4 and IPv6-enabled products when it is cost effective to do so".
It has been estimated that the transition will cost £33bn, and the likelihood is that it will take place gradually as network infrastructures are replaced. Some carriers are installing dual-protocol networks, and the expectation is that IPv4 and IPv6 will coexist for a long time.
Where did it originate?
Work began on the successor to IPv4 in the early 1990s. IPv6 has been with us since the late 1990s, and it was first implemented in Linux and IBM's AIX.
What's it for?
The most obvious benefit of IPv6 is the increase in the number of IP addresses. IPv4, with 32-bit address spaces, provides four billion addresses. Predictions for when addresses will run out vary from 2010 to 2020, with the possibility of extending the life of IPv4 by recycling unused addresses.
IPv6 brings 128-bit addresses, expanding the potential to trillions to take account of a world filled with internet-enabled devices.
More recently, the emphasis has shifted to the benefits of end-to-end connectivity and end-to-end security through IPsec - the integral security capabilities that had to be tacked on to IPv4.
What makes it special?
IPv6 has been described as a step back to a simpler, cheaper network, but the transition is shaping up to be neither simple or cheap.
How difficult is it to master?
IPv4 practitioners can learn IPv6 on a four-day course. IPv6 is described as "a conservative extension" of IPv4, not a revolutionary replacement.However, users of Vista have found the transition is more complicated than this would suggest. Microsoft recommends that users spend at least a year testing IPv4 and IPv6 coexistence before putting it into production, and a similar length of time familiarising themselves with IPv6 to reap the full benefits.
People with transition experience are going to be in demand.
What systems does it run on?
Most new IT communications equipment, and all mainstream operating systems support IPv6. There are problems with file and print tasks involving devices that do not support it.
What's coming up?
Windows Server 2008 will be IPv6-enabled, providing IPv6 support to Exchange.
Training is available from major equipment suppliers, their partners and many independent training companies. The UK IPv6 Task Force has good resources on the internet.
Rates of pay
Junior IP network engineers can earn from £25,000. Senior engineers and network architects can command salaries of £50,000 or more.