Editing IPv6 (section)

{{short description|Version 6 of the Internet Protocol}}
{{Update|part=RFC 8200 and RFC 8201|date=July 2017}}
{{Use dmy dates|date=September 2020}}
{{Infobox networking protocol
| title        = Internet Protocol version 6
| logo         =
| logo alt     =
| image        = [[File:IPv6 header-en.svg|class=skin-invert-image|300px|alt=Diagram of an IPV6 header]]
| image alt    = Diagram of an IPv6 header
| caption      = IPv6 header
| is stack     = yes
| abbreviation = IPv6
| purpose      = [[Internetworking]] protocol
| developer    = [[Internet Engineering Task Force]]
| date         = {{Start date and age|df=yes|1995|12|}}<!--Fill in: Year (4 digits), month and day (2 digits)-->
| based on     = [[IPv4]]
| influenced   =
| osilayer     = [[Network layer]]
| ports        =
| rfcs         = {{IETF RFC|2460|8200|plainlink=yes}}
| hardware     =
}}
{{Internet protocol suite}}
{{Internet history timeline}}

'''Internet Protocol version 6''' ('''IPv6''') is the most recent version of the [[Internet Protocol]] (IP), the [[communication protocol|communications protocol]] that provides an identification and location system for computers on networks and routes traffic across the [[Internet]]. IPv6 was developed by the [[Internet Engineering Task Force]] (IETF) to deal with the long-anticipated problem of [[IPv4 address exhaustion]], and was intended to replace [[IPv4]].<ref name="ipv6nz">{{cite web|url=https://www.ipv6.org.nz/ipv6-faqs/|title=FAQs|publisher=New Zealand IPv6 Task Force|access-date=26 October 2015|archive-date=29 January 2019|archive-url=https://web.archive.org/web/20190129005124/http://www.ipv6.org.nz/ipv6-faqs/|url-status=dead}}</ref> In December 1998, IPv6 became a Draft Standard for the IETF,<ref name="rfc2460"/> which subsequently ratified it as an [[Internet Standard]] on 14 July 2017.<ref name="rfc8200"/><ref>{{Cite web |last=Siddiqui |first=Aftab |date=17 July 2017 |title=RFC 8200 – IPv6 Has Been Standardized |url=https://www.internetsociety.org/blog/2017/07/rfc-8200-ipv6-has-been-standardized/ |url-status=live |archive-url=https://web.archive.org/web/20231023162212/https://www.internetsociety.org/blog/2017/07/rfc-8200-ipv6-has-been-standardized/ |archive-date=23 October 2023 |access-date=25 February 2018 |publisher=[[Internet Society]] }}</ref>

Devices on the Internet are assigned a unique [[IP address]] for identification and location definition. With the rapid growth of the Internet after commercialization in the 1990s, it became evident that far more addresses would be needed to connect devices than the 4,294,967,296 (2<sup>32</sup>) IPv4 address space had available. By 1998, the IETF had formalized the successor protocol, IPv6 which uses 128-[[bit]] addresses, theoretically allowing 2<sup>128</sup>, or 340,282,366,920,938,463,463,374,607,431,768,211,456 total addresses. The actual number is slightly smaller, as multiple ranges are reserved for special usage or completely excluded from general use. The two protocols are not designed to be [[interoperable]], and thus direct communication between them is impossible, complicating the move to IPv6. However, several [[IPv6 transition mechanism|transition mechanisms]] have been devised to rectify this.

IPv6 provides other technical benefits in addition to a larger addressing space. In particular, it permits hierarchical address allocation methods that facilitate [[route aggregation]] across the Internet, and thus limit the expansion of [[routing table]]s. The use of multicast addressing is expanded and simplified, and provides additional optimization for the delivery of services. Device mobility, security, and configuration aspects have been considered in the design of the protocol.

IPv6 addresses are represented as eight groups of four [[hexadecimal]] digits each, separated by colons. The full representation may be shortened; for example, {{IPaddr|2001:0db8:0000:0000:0000:8a2e:0370:7334}} becomes {{IPaddr|2001:db8::8a2e:370:7334}}.

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