Special-Use IPv6 Addresses

This document describes the global and other specialized IPv6 address blocks.It does not address IPv6 address space assigned to operators and users through the Regional Internet Registries. These descriptions are useful for route and IP filtering, for documentation and other purposes. The document is structured by address types. The document format is similar to . Some tips about filtering are given, but are not mandatory to implement. The addresses listed in this document must not be hard coded into implementations.

::1/128 is the loopback address . ::/128 is the unspecified address . Addresses within this block should not appear on the public Internet.

::FFFF:0:0/96 are the IPv4-mapped addresses . Addresses within this block should not appear on the public Internet.

::ipv4-address/96 are the IPv4-compatible addresses . These addresses are deprecated and should not appear on the public Internet.

fe80::/10 are the link-local unicast addresses. Addresses within this block should not appear on the public Internet.

fc00::/7 are the unique-local addresses . Addresses within this block should not appear by default on the public Internet. Procedure for advertising these addresses are further described in .

The 2001:db8::/32 are the documentation addresses . They are used for documentation purposes such as user manuals, RFCs, etc. Addresses within this block should not appear on the public Internet.

2002::/16 are the 6to4 addresses . The 6to4 addresses may be advertised when the site is running a 6to4 relay or offering a 6to4 transit service. However, the provider of this service should be aware of the implications of running such service, which include some specific filtering rules for 6to4. IPv4 addresses disallowed in 6to4 prefixes are listed in section 5.3.1 of .

2001::/32 are the Teredo addresses . The Teredo addresses may be advertised when the site is running a Teredo relay or offering a Teredo transit service.

5f00::/8 were the addresses of the first instance of the 6bone experimental network . 3ffe::/16 were the addresses of the second instance of the 6bone experimental network . Both 5f00::/8 and 3ffe::/16 were returned to IANA . These addresses are subject to future allocation, similar to current unallocated address space. Addresses within this block should not appear on the public Internet until they are reallocated.

2001:10::/28 are ORCHID addresses . These addresses are used as identifiers and are not routable at the IP layer. Addresses within this block should not appear on the public Internet.

::/0 is the default unicast route address.

An IANA registry (iana-ipv6-special-registry) is set for Special Purpose IPv6 address blocks assignments used for experiments and other purposes. Addresses within this registry should be reviewed for Internet routing considerations.

ff00::/8 are multicast addresses . They have a 4 bits scope in the address field where only some value are of global scope . Only addresses with global scope in this block may appear on the public Internet. Multicast routes must not appear in unicast routing tables.

This document lists addresses and guidelines associated with them. The guidelines should improve the security of networks by the filtering of invalid routing prefixes.

To ensure consistency and to provide cross-referencing for the benefit of the community, IANA is requested to insert the following paragraph in the header of the iana-ipv6-special registry. "Other special IPv6 addresses requiring specific considerations for global routing are listed in RFCXXXX." NOTE TO RFC EDITOR and IANA: replace RFCXXXX by the assigned RFC number of this document.

Florent Parent, Pekka Savola, Tim Chown, Alain Baudot, Stig Venaas, Vincent Jardin, Olaf Bonness, David Green, Gunter Van de Velde, Michael Barnes, Fred Baker, Edward Lewis, Marla Azinger, Brian Carpenter, Mark Smith, Kevin Loch, Alain Durand, Jim Bound, Peter Sherbin, Bob Hinden, Gert Doering, Niall O'Reilly, Mark Townsley and Jari Arkko have provided input and suggestions to this document.