In addition to offering more addresses, IPv6 also implements features not present in IPv4.It simplifies aspects of address assignment (stateless address autoconfiguration), network renumbering, and router announcements when changing network connectivity providers.
However, several IPv6 transition mechanisms have been devised to permit communication between IPv4 and IPv6 hosts.
IPv6 provides other technical benefits in addition to a larger addressing space.
Thus, IPv4 provides an addressing capability of 2 During the first decade of operation of the Internet, it became apparent that methods had to be developed to conserve address space.
In the early 1990s, even after the redesign of the addressing system using a classless network model, it became clear that this would not suffice to prevent IPv4 address exhaustion, and that further changes to the Internet infrastructure were needed.
Allard (Microsoft), Steve Bellovin (AT&T), Jim Bound (Digital Equipment Corporation), Ross Callon (Wellfleet), Brian Carpenter (CERN), Dave Clark (MIT), John Curran (NEARNET), Steve Deering (Xerox), Dino Farinacci (Cisco), Paul Francis (NTT), Eric Fleischmann (Boeing), Mark Knopper (Ameritech), Greg Minshall (Novell), Rob Ullmann (Lotus), and Lixia Zhang (Xerox).
By 1996, a series of RFCs was released defining Internet Protocol version 6 (IPv6), starting with RFC 1883.
Network security was a design requirement of the IPv6 architecture, and included the original specification of IPsec.
IPv6 does not specify interoperability features with IPv4, but essentially creates a parallel, independent network.
This leaves African Network Information Center (AFRINIC) as the sole regional internet registry that is still using the normal protocol for distributing IPv4 addresses.
By the beginning of 1992, several proposals appeared for an expanded Internet addressing system and by the end of 1992 the IETF announced a call for white papers.
IPv6 uses a 128-bit address, theoretically allowing 2 times as many as IPv4, which uses 32-bit addresses and provides approximately 4.3 billion addresses.