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.
References: RFC 4773, RFC 6890, RFC 8190
| Value | Defined by | Name | Description | References |
|---|---|---|---|---|
| ::/128 | IANA | Unspecified Address | - | RFC 4291 |
| ::1/128 | IANA | Loopback Address | - | RFC 4291 |
| ::ffff:0:0/96 | IANA | IPv4-mapped Address | - | RFC 4291 |
| 64:ff9b::/96 | IANA | IPv4-IPv6 Translat. | - | RFC 6052 |
| 64:ff9b:1::/48 | IANA | IPv4-IPv6 Translat. | - | RFC 8215 |
| 100::/64 | IANA | Discard-Only Address Block | - | RFC 6666 |
| 2001::/32 | IANA | TEREDO | - | RFC 4380, RFC 8190 |
| 2001::/23 | IANA | IETF Protocol Assignments | - | RFC 2928 |
| 2001:1::1/128 | IANA | Port Control Protocol Anycast | - | RFC 7723 |
| 2001:1::2/128 | IANA | Traversal Using Relays around NAT Anycast | - | RFC 8155 |
| 2001:2::/48 | IANA | Benchmarking | - | RFC 5180, RFC Errata 1752 |
| 2001:3::/32 | IANA | AMT | - | RFC 7450 |
| 2001:4:112::/48 | IANA | AS112-v6 | - | RFC 7535 |
| 2001:10::/28 | IANA | Deprecated (previously ORCHID) | - | RFC 4843 |
| 2001:20::/28 | IANA | ORCHIDv2 | - | RFC 7343 |
| 2001:30::/28 | IANA | Drone Remote ID Protocol Entity Tags (DETs) Prefix | - | RFC 9374 |
| 2001:db8::/32 | IANA | Documentation | - | RFC 3849 |
| 2002::/16 | IANA | 6to4 | - | RFC 3056 |
| 2620:4f:8000::/48 | IANA | Direct Delegation AS112 Service | - | RFC 7534 |
| fc00::/7 | IANA | Unique-Local | - | RFC 4193, RFC 8190 |
| fd00::/8 | Ungleich | ULA Registry | While is is debatable whether or not there should be a ULA registry at all, ungleich was frequently asked to provide a ULA registry for those who don't have the resources to use global unique addresses, but still want to indicate that a network is used.
Registration of ULA space is not required! This is a informational registry. |
ula.ungleich.ch |
| fe80::/10 | IANA | Link-Local Unicast | - | RFC 4291 |