IPv6 is the next generation internet protocol.
Most of today’s internet uses IPv4, which is now nearly twenty years old. IPv4 has been remarkably resilient in spite of its age, but it is beginning to have problems. Most importantly, there is a growing shortage of IPv4 addresses, which are needed by all new machines added to the Internet.
IPv6 fixes a number of problems in IPv4, such as the limited number of available IPv4 addresses. It also adds many improvements to IPv4 in areas such as routing and network autoconfiguration. IPv6 is expected to gradually replace IPv4, with the two coexisting for a number of years during a transition period.
The main improvement brought by IPv6 is the increase in the number of addresses available for networked devices, allowing, for example, each cell phone and mobile electronic device to have its own address. IPv4 supports 4.3×109 (4.3 billion) addresses, which is inadequate for giving even one address to every living person, much less support the burgeoning emerging market for connective devices. IPv6 supports 3.4×1038 addresses, or 5×1028(50 octillion) for each of the roughly 6.5 billion people alive today, or about 800 addresses for each gram of matter in the Earth.