Internet Assigned Numbers Authority

IP Version Numbers

Last Updated
2021-01-28
Note
In the Internet Protocol (IP) [RFC791][RFC8200] there is a field to identify
the version of the internetwork general protocol.  This field is 4
bits in size.
  
Available Formats

XML

HTML

Plain text

Registry included below

IP Version Numbers

Registration Procedure(s)
Standards Action
Reference
[RFC2780]
Available Formats

CSV
Decimal Keyword Version Reference
0-1 Reserved [Jon_Postel][RFC4928]
2-3 Unassigned [Jon_Postel]
4 IP Internet Protocol [RFC791][Jon_Postel]
5 Reserved (Historic) [RFC1819][Moving IP versions 5, 8, and 9 to Historic]
6 IPv6 Internet Protocol version 6 [RFC8200]
7 Reserved (Historic) [RFC1475][RFC6814]
8 Reserved (Historic) [RFC1621][Moving IP versions 5, 8, and 9 to Historic]
9 Reserved (Historic) [RFC1347][Moving IP versions 5, 8, and 9 to Historic]
10-14 Unassigned [Jon_Postel]
15 Reserved [Jon_Postel]

Contact Information

ID Name Contact URI Last Updated
[Jon_Postel] Jon Postel mailto:postel&isi.edu