P is the common element found in today's public Internet. The current and most popular network layer protocol in use today is IPv4; this version of the protocol is assigned version 4. IPv4 is described in RFC-791 (1981).
IPv6 is the proposed successor to IPv4 whose most prominent change is the addressing. IPv4 uses 32-bit addresses (~4 billion addresses) while IPv6 uses 128-bit addresses (~3.4×1038 addresses). Although adoption of IPv6 has been slow, as of 2008, all United States government systems must support IPv6 (if only at the backbone level).
Version numbers 0 through 3 were development versions of IPv4 used between 1977 and 1979. Version number 5 was used by the Internet Stream Protocol (IST), an experimental stream protocol. Version numbers 6 through 9 were assigned to experimental protocols designed to replace IPv4: SIPP (known nowadays as IPv6), TP/IX, PIP, and TUBA. Of these, only IPv6 is still in use.
No comments:
Post a Comment