Editing Internet Protocol (section)

===IP version numbers===
As the version number is carried in a 4-bit field, only numbers 0–15 can be assigned.
{| class="wikitable"
|-
!IP version
!Description
!Year
!Status
|-
!0
|Internet Protocol, pre-v4||N/A||Reserved<ref name="routing tcp/ip">{{Cite book|title=Routing TCP/IP|volume=1|edition=2|author1=Jeff Doyle|author2=Jennifer Carroll|year=2006|isbn=978-1-58705-202-6|publisher=Cisco Press|page=8}}</ref>
|-
!1
|Experimental version||1973||Obsolete
|-
!2
|Experimental version||1977||Obsolete
|-
!3
|Experimental version||1978||Obsolete
|-
!4
|[[Internet Protocol version 4]] (IPv4){{Ref RFC|791|repeat=yes}}||1981||Active
|-
!rowspan=3|5
|[[Internet Stream Protocol]] (ST)||1979||Obsolete; superseded by ST-II or ST2
|-
|[[Internet Stream Protocol]] (ST-II or ST2){{Ref RFC|1819}}||1987||Obsolete; superseded by ST2+
|-
|[[Internet Stream Protocol]] (ST2+)||1995||Obsolete
|-
!rowspan=2|6
|Simple Internet Protocol (SIP)||N/A||Obsolete; merged into IPv6 in 1995<ref name="routing tcp/ip" />
|-
|[[Internet Protocol version 6]] (IPv6){{Ref RFC|8200|repeat=yes}}||1995||Active
|-
!7
|TP/IX The Next Internet (IPv7){{Ref RFC|1475}}||1993||Obsolete{{Ref RFC|6814}}
|-
!8
|P Internet Protocol (PIP){{Ref RFC|1621}}||1994||Obsolete; merged into SIP in 1993
|-
!rowspan=3|9
|TCP and UDP over Bigger Addresses (TUBA)||1992||Obsolete{{Ref RFC|1347}}
|-
|IPv9||1994||[[April Fools' Day]] joke{{Ref RFC|1606}}
|-
|[[Chinese IPv9]]||2004||Abandoned
|-
!10–14
|N/A||N/A||Unassigned
|-
!15
|''Version field sentinel value''||N/A||Reserved
|}