IPv6
IPv6 is short for "Internet Protocol Version 6". IPv6 is the "next generation" protocol designed by the IETF to replace the current version Internet Protocol, IP Version 4 ("IPv4").
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, by mean of 128 bits 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 coexistence and transition period.
The development of IPv6 and bigger addresses bring new benefits such as:
- Easy address-autoconfiguration ("plug and play") and re-configuration
- Easier address management/delegation
- Room for more levels of hierarchy for route aggregation
- Built-in, strong IP-layer encryption and authentication (IPsec)
- Ability to do end-to-end IPsec (because NATs not needed)
- Reduced complexity, e.g., in IP header
- Upgrade in functionalities related to multicast, mobility and QoS
- Improved support for extensions/options