RFCs such as 5952 - "A Recommendation for IPv6 Address Text Representation" and 2373 - "IP Version 6 Addressing Architecture" each outline the commonly used hexadecimal and colon based notation that is typically used for representing an IPv6 address, or the leading portion of an IPv6 CIDR.

E.g. 2001:0db8:85a3::8a2e:0370:7334.

However, the RFCs do not appear to suggest a name for this ubiquitous format. Is there a name for this format, similar to how IPv4 has a named dot-decimal notation? If so, what is the proper name to use when referring to this standard IPv6 notation?

  • I'm seeing lots of hits on google for Coloned Hexadecimal, but have no authoritative source for it. – Eddie Feb 9 '16 at 20:28
  • Also seeing this quote in RFC 5952 which might offer a clue since it compares it with dotted decimal in IPv4: These addresses have a special representation that may mix hexadecimal and dot decimal notation – Eddie Feb 9 '16 at 20:30
  • Well, it's called a "text representation". Probably not as clear as "dot decimal", though. – jcaron Feb 10 '16 at 0:25

RFC 5952 gives you the canonical IPv6 format. That is explained in the RFC itself:

This document defines a canonical textual representation format.


4. A Recommendation for IPv6 Text Representation

A recommendation for a canonical text representation format of IPv6 addresses is presented in this section.

There are people who incorrectly call a fully uncompressed (eight words of four hexadecimal digits each) the canonical format but the RFC refer to this as conventional notation.

When zero words are replaced with :: it is a compressed address format, and when used with IPv4 notation, such as ::ffff: it is a mixed, or compressed and mixed, address format.

Edit based on the question edit:

There is no official name for the IPv6 notation, but RFC 5952, among others, refers to it as hexadecimal notation.

Even the IPv4 address notation commonly called dotted-decimal notation is not really in any RFC defining IPv4. It is mentioned in RFC 3795, Survey of IPv4 Addresses in Currently Deployed IETF Application Area Standards Track and Experimental Documents, an informational RFC which specifically states:

This memo provides information for the Internet community. It does not specify an Internet standard of any kind.

In conclusion, there is no official name for the general IPv6 format, and you may call it whatever you wish. I think it is important to distinguish between the various IPv6 address formats. My company has a requirement to use the RFC 5952 canonical format rather than the conventional format.

Note: I left the rest of my answer in as useful information.

  • 4
    I believe the OP is looking for the IPv6 equivalent of Dotted Decimal notation for IPv4. – Eddie Feb 9 '16 at 20:25
  • I don't see it that way since the OP specifically asks about RFC 5952 rather than the flexible IPv6 format from RFCs 1884, 2373, 3513, 4291, etc. which define the standard IPv6 addressing format and also uses hexadecimal and colons. – Ron Maupin Feb 9 '16 at 20:37
  • @Eddie that is exactly what I'm looking for, will edit the question to be more explicit – rheone Feb 9 '16 at 20:55
  • Correct. It is says that you may mix the hexadecimal notation used for IPv6 addresses with the dot decimal notation used for IPv4 addresses. That says to me that the IETF considers IPv6 address notation to be hexadecimal notation, and the IPv4 address notation to be dot decimal notation. Most people call the most commonly used IPv4 address notation dotted decimal, which is not what RFC 5952 uses for it. – Ron Maupin Feb 9 '16 at 21:31

i don't think this is an answer for the question regarding the overall name for ipv6 address, but I will say that i've heard of one section of the dotted-decimal/quad of v4 which is octet, I've heard octet equate to ipv6 hextet. as far as one of the sections of the v6 address... 4 hex characters combined are referred to as a hextet.


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