Internet Assigned Numbers Authority IANA IPv6 Special-Purpose Address Registry Created 2006-01-10 Last Updated 2025-04-30 Available Formats [IMG] XML [IMG] HTML [IMG] Plain text Registry included below • IANA IPv6 Special-Purpose Address Registry IANA IPv6 Special-Purpose Address Registry Registration Procedure(s) IETF Review Reference [RFC4773][RFC6890][RFC8190] 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. Available Formats [IMG] CSV Address Block Name RFC Allocation Termination Source Destination Forwardable Globally Reserved-by-Protocol Date Date Reachable ::1/128 Loopback [RFC4291] 2006-02 N/A False False False False True Address ::/128 Unspecified [RFC4291] 2006-02 N/A True False False False True Address ::ffff:0:0/96 IPv4-mapped [RFC4291] 2006-02 N/A False False False False True Address 64:ff9b::/96 IPv4-IPv6 [RFC6052] 2010-10 N/A True True True True False Translat. 64:ff9b:1::/48 IPv4-IPv6 [RFC8215] 2017-06 N/A True True True False False Translat. 100::/64 Discard-Only [RFC6666] 2012-06 N/A True True True False False Address Block 100:0:0:1::/64 Dummy IPv6 [RFC-ietf-mpls-p2mp-bfd-11] 2025-04 N/A True False False False False Prefix 2001::/23 IETF Protocol [RFC2928] 2000-09 N/A False False [1] False [1] False [1] False Assignments [1] 2001::/32 TEREDO [RFC4380] [RFC8190] 2006-01 N/A True True True N/A [2] False Port Control 2001:1::1/128 Protocol [RFC7723] 2015-10 N/A True True True True False Anycast Traversal 2001:1::2/128 Using Relays [RFC8155] 2017-02 N/A True True True True False around NAT Anycast DNS-SD Service 2001:1::3/128 Registration [RFC-ietf-dnssd-srp-25] 2024-04 N/A True True True True False Protocol Anycast 2001:2::/48 Benchmarking [RFC5180][RFC Errata 1752] 2008-04 N/A True True True False False 2001:3::/32 AMT [RFC7450] 2014-12 N/A True True True True False 2001:4:112::/48 AS112-v6 [RFC7535] 2014-12 N/A True True True True False Deprecated 2001:10::/28 (previously [RFC4843] 2007-03 2014-03 ORCHID) 2001:20::/28 ORCHIDv2 [RFC7343] 2014-07 N/A True True True True False Drone Remote 2001:30::/28 ID Protocol [RFC9374] 2022-12 N/A True True True True False Entity Tags (DETs) Prefix 2001:db8::/32 Documentation [RFC3849] 2004-07 N/A False False False False False 2002::/16 [3] 6to4 [RFC3056] 2001-02 N/A True True True N/A [3] False Direct 2620:4f:8000::/48 Delegation [RFC7534] 2011-05 N/A True True True True False AS112 Service 3fff::/20 Documentation [RFC9637] 2024-07 N/A False False False False False Segment 5f00::/16 Routing [RFC9602] 2024-04 N/A True True True False False (SRv6) SIDs fc00::/7 Unique-Local [RFC4193] [RFC8190] 2005-10 N/A True True True False [4] False fe80::/10 Link-Local [RFC4291] 2006-02 N/A True True False False True Unicast Footnotes [1] Unless allowed by a more specific allocation. [2] See Section 5 of [RFC4380] for details. [3] See [RFC3056] for details. [4] See [RFC4193] 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. Licensing Terms