IPv6 is the Internet Engineering Task Force's next-generation Internet communications protocol.
IPv6 has a 128-bit address space versus IPv4's 32-bit space, which will allow for a geometric increase in the number of possible addresses. This means a far greater number of users will be able to tie directly into the 'Net. It should also increase the scalability of IP-based networks in the corporate environment.
IPv6 will also divvy up addresses differently. The idea is to reserve groups of addresses for specific types of use and leave lots of unallocated address space for future growth. For example, IPv4 devices will keep their existing eight-digit designations, but ISPs will get a three-digit code that will remain unique to those vendors. Other designations will be reserved for local use or deployment by devices that support advanced functions such as multicast operations.
IPv6 will also enable host machines to automatically discover the information, such as the address of a local router, needed to connect to the Internet or corporate IP backbone. Analysts at Forrester Research say that this feature alone will eliminate so much manual configuration minutia from users' lives it will pay back the cost of converting to IPv6-based technology within a year.
Addressing isn't the only issue being addressed in IPv6. In order to speed up IPv6 transmissions, the protocol's header has been greatly simplified with unused fields being made optional. Headers are the part of a transmission that guide data to its proper destination. With this improved header, data should traverse IP-based nets much more quickly and with less overhead.
Other new components of IPv6 include technology that would prioritize the flow of IP-based traffic over an TCP/IP backbone. Called "flow labeling," the feature would provide a standard way for workstations or hosts to specify special handling of certain traffic types. The feature is important for future multimedia or other applications that generate lots of interactive traffic. For example, an important videoconference could be labeled to ensure it receives transmission priority over, say, routing remote file transfers.
Additional resources
IPv6 Forum
Industry group.
IPv6: Dual stack where you can; tunnel where you must
