Internet Protocol Version 6 Address Space

Last Updated
2013-02-15
Note
The IPv6 address management function was formally delegated to
IANA in December 1995 [RFC1881]. The registration procedure
was confirmed with the IETF Chair in March 2010.
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Registration Procedure(s)
IESG Approval
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IPv6 Prefix Allocation Reference Notes
0000::/8 Reserved by IETF [RFC4291] [1] [2] [3] [4] [5]
0100::/8 Reserved by IETF [RFC4291] 0100::/64 reserved for Discard-Only Address Block [RFC6666]. Complete registration details are found in [IANA registry iana-ipv6-special-registry].
0200::/7 Reserved by IETF [RFC4048] Deprecated as of December 2004 [RFC4048]. Formerly an OSI NSAP-mapped prefix set [RFC4548].
0400::/6 Reserved by IETF [RFC4291]
0800::/5 Reserved by IETF [RFC4291]
1000::/4 Reserved by IETF [RFC4291]
2000::/3 Global Unicast [RFC4291] The IPv6 Unicast space encompasses the entire IPv6 address range with the exception of ff00::/8, per [RFC4291]. IANA unicast address assignments are currently limited to the IPv6 unicast address range of 2000::/3. IANA assignments from this block are registered in [IANA registry ipv6-unicast-address-assignments]. [6] [7] [8] [9] [10] [11]
4000::/3 Reserved by IETF [RFC4291]
6000::/3 Reserved by IETF [RFC4291]
8000::/3 Reserved by IETF [RFC4291]
a000::/3 Reserved by IETF [RFC4291]
c000::/3 Reserved by IETF [RFC4291]
e000::/4 Reserved by IETF [RFC4291]
f000::/5 Reserved by IETF [RFC4291]
f800::/6 Reserved by IETF [RFC4291]
fc00::/7 Unique Local Unicast [RFC4193] For complete registration details, see [IANA registry iana-ipv6-special-registry].
fe00::/9 Reserved by IETF [RFC4291]
fe80::/10 Link-Scoped Unicast [RFC4291] Reserved by protocol. For authoritative registration, see [IANA registry iana-ipv6-special-registry].
fec0::/10 Reserved by IETF [RFC3879] Deprecated by [RFC3879] in September 2004. Formerly a Site-Local scoped address prefix.
ff00::/8 Multicast [RFC4291] IANA assignments from this block are registered in [IANA registry ipv6-multicast-addresses].

Footnotes

[1]
::1/128 reserved for Loopback Address [RFC4291]. 
Reserved by protocol. For authoritative registration, see [IANA registry iana-ipv6-special-registry].
[2]
::/128 reserved for Unspecified Address [RFC4291]. 
Reserved by protocol. For authoritative registration, see [IANA registry iana-ipv6-special-registry].
[3]
::ffff:0:0/96 reserved for IPv4-mapped Address [RFC4291]. 
Reserved by protocol. For authoritative registration, see [IANA registry iana-ipv6-special-registry].
[4]
0000::/96 deprecated by [RFC4291]. Formerly defined as the "IPv4-compatible IPv6 address" prefix.
[5]
The "Well Known Prefix" 64:ff9b::/96 is used in an algorithmic mapping between IPv4 to IPv6 addresses [RFC6052].
[6]
2001:0000::/23 reserved for IETF Protocol Assignments [RFC2928]. 
For complete registration details, see [IANA registry iana-ipv6-special-registry].
[7]
2001:0000::/32 reserved for TEREDO [RFC4380]. 
For complete registration details, see [IANA registry iana-ipv6-special-registry].
[8]
2001:0002::/48 reserved for Benchmarking [RFC5180]. 
For complete registration details, see [IANA registry iana-ipv6-special-registry].
[9]
2001:db8::/32 reserved for Documentation [RFC3849]. 
For complete registration details, see [IANA registry iana-ipv6-special-registry].
[10]
2001:10::/28 reserved for ORCHID [RFC4843]. 
For complete registration details, see [IANA registry iana-ipv6-special-registry].
[11]
2002::/16 reserved for 6to4 [RFC3056]. 
For complete registration details, see [IANA registry iana-ipv6-special-registry].