IPv6 Special-Purpose Address Space

Created
2006-01-10
Last Updated
2025-10-09
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Registry Included Below

IPv6 Special-Purpose Address Space

Registration Procedure(s)
IETF Review
Reference
[RFC 4773][RFC 6890][RFC 8190]
Note
Address prefixes listed in the Special-Purpose Address Registry are
not guaranteed routability in any particular local or global context.

The IPv4 and IPv6 Special-Purpose Address Registries maintain the following 
information regarding each entry:

   o  Address Block - A block of IPv4 or IPv6 addresses that has been
      registered for a special purpose.

   o  Name - A descriptive name for the special-purpose address block.

   o  RFC - The RFC through which the special-purpose address block was
      requested.

   o  Allocation Date - The date upon which the special-purpose address
      block was allocated.

   o  Termination Date - The date upon which the allocation is to be
      terminated.  This field is applicable for limited-use allocations
      only.

   o  Source - A boolean value indicating whether an address from the
      allocated special-purpose address block is valid when used as the
      source address of an IP datagram that transits two devices.

   o  Destination - A boolean value indicating whether an address from
      the allocated special-purpose address block is valid when used as
      the destination address of an IP datagram that transits two
      devices.

   o  Forwardable - A boolean value indicating whether a router may
      forward an IP datagram whose destination address is drawn from the
      allocated special-purpose address block between external
      interfaces.

   o  Globally Reachable - A boolean value indicating whether an IP 
      datagram whose destination address is drawn from the allocated 
      special-purpose address block is forwardable beyond a specified 
      administrative domain.

   o  Reserved-by-Protocol - A boolean value indicating whether the
      special-purpose address block is reserved by IP, itself.  This
      value is "TRUE" if the RFC that created the special-purpose
      address block requires all compliant IP implementations to behave
      in a special way when processing packets either to or from
      addresses contained by the address block.

If the value of "Destination" is FALSE, the values of "Forwardable" and 
"Globally Reachable" must also be false.

Formerly known as
IANA IPv6 Special-Purpose Address Registry (pursuant to [IESG decision])
Available Formats

CSV
Address Block Name RFC Allocation Date Termination Date Source Destination Forwardable Globally Reachable Reserved-by-Protocol
::1/128 Loopback Address [RFC 4291] 2006-02 N/A False False False False True
::/128 Unspecified Address [RFC 4291] 2006-02 N/A True False False False True
::ffff:0:0/96 IPv4-mapped Address [RFC 4291] 2006-02 N/A False False False False True
64:ff9b::/96 IPv4-IPv6 Translat. [RFC 6052] 2010-10 N/A True True True True False
64:ff9b:1::/48 IPv4-IPv6 Translat. [RFC 8215] 2017-06 N/A True True True False False
100::/64 Discard-Only Address Block [RFC 6666] 2012-06 N/A True True True False False
100:0:0:1::/64 Dummy IPv6 Prefix [RFC 9780] 2025-04 N/A True False False False False
2001::/23 IETF Protocol Assignments [RFC 2928] 2000-09 N/A False [1] False [1] False [1] False [1] False
2001::/32 TEREDO [RFC 4380] [RFC 8190] 2006-01 N/A True True True N/A [2] False
2001:1::1/128 Port Control Protocol Anycast [RFC 7723] 2015-10 N/A True True True True False
2001:1::2/128 Traversal Using Relays around NAT Anycast [RFC 8155] 2017-02 N/A True True True True False
2001:1::3/128 DNS-SD Service Registration Protocol Anycast [RFC 9665] 2024-04 N/A True True True True False
2001:2::/48 Benchmarking [RFC 5180][RFC Errata 1752] 2008-04 N/A True True True False False
2001:3::/32 AMT [RFC 7450] 2014-12 N/A True True True True False
2001:4:112::/48 AS112-v6 [RFC 7535] 2014-12 N/A True True True True False
2001:10::/28 Deprecated (previously ORCHID) [RFC 4843] 2007-03 2014-03
2001:20::/28 ORCHIDv2 [RFC 7343] 2014-07 N/A True True True True False
2001:30::/28 Drone Remote ID Protocol Entity Tags (DETs) Prefix [RFC 9374] 2022-12 N/A True True True True False
2001:db8::/32 Documentation [RFC 3849] 2004-07 N/A False False False False False
2002::/16 [3] 6to4 [RFC 3056] 2001-02 N/A True True True N/A [3] False
2620:4f:8000::/48 Direct Delegation AS112 Service [RFC 7534] 2011-05 N/A True True True True False
3fff::/20 Documentation [RFC 9637] 2024-07 N/A False False False False False
5f00::/16 Segment Routing (SRv6) SIDs [RFC 9602] 2024-04 N/A True True True False False
fc00::/7 Unique-Local [RFC 4193] [RFC 8190] 2005-10 N/A True True True False [4] False
fe80::/10 Link-Local Unicast [RFC 4291] 2006-02 N/A True True False False True

Footnotes

[1]
Unless allowed by a more specific allocation.
[2]
See Section 5 of [RFC 4380] for details.
[3]
See [RFC 3056] for details.
[4]
See [RFC 4193] for more details on the routability of Unique-Local addresses.  The Unique-Local prefix is 
drawn from the IPv6 Global Unicast Address range, but is specified as not globally routed.