Internet Protocol Version 6 Address Space
2024-09-10
The IPv6 address management function was formally delegated to IANA
in December 1995 . The registration procedure was confirmed
with the IETF Chair in March 2010.
As stated in , IANA should limit its allocation of
IPv6-unicast address space to the range of addresses that start with
binary value 001. The rest of the global unicast address space
(approximately 85% of the IPv6 address space) is reserved for future
definition and use, and is not to be assigned by IANA at this time.
While was obsoleted by , the guidance provided to
IANA did not change regarding the allocation of IPv6 unicast
addresses.
IESG Approval
::/8
Reserved by IETF
This range has been partially allocated. See for details. ::/96, formerly defined as the "IPv4-compatible IPv6 address" prefix, was deprecated by .
100::/8
Reserved by IETF
This range has been partially allocated. See for details.
200::/7
Reserved by IETF
Deprecated as of December 2004 . Formerly an OSI NSAP-mapped prefix set .
400::/6
Reserved by IETF
800::/5
Reserved by IETF
1000::/4
Reserved by IETF
2000::/3
Global Unicast
The IPv6 Unicast space encompasses the entire IPv6 address range
with the exception of ff00::/8, per . IANA unicast address
assignments are currently limited to the IPv6 unicast address
range of 2000::/3. IANA assignments from this block are registered
in .
4000::/3
Reserved by IETF
This range has been partially allocated. See for details. 5f00::/8 (with 3ffe::/16, as noted at ) was used for the 6bone, but returned .
6000::/3
Reserved by IETF
8000::/3
Reserved by IETF
a000::/3
Reserved by IETF
c000::/3
Reserved by IETF
e000::/4
Reserved by IETF
f000::/5
Reserved by IETF
f800::/6
Reserved by IETF
fc00::/7
Unique Local Unicast
See for details.
fe00::/9
Reserved by IETF
fe80::/10
Link-Scoped Unicast
See for details.
fec0::/10
Reserved by IETF
Deprecated by in September 2004. Formerly a Site-Local scoped address prefix.
ff00::/8
Multicast
See for details.