





Internet Engineering Task Force (IETF)                         M. Cotton
Request for Comments: 6890                                     L. Vegoda
BCP: 153                                                           ICANN
Obsoletes: 4773, 5156, 5735, 5736                         R. Bonica, Ed.
Category: Best Current Practice                         Juniper Networks
ISSN: 2070-1721                                              B. Haberman
                                                                     JHU
                                                              April 2013


                 Special-Purpose IP Address Registries

Abstract

   This memo reiterates the assignment of an IPv4 address block
   (192.0.0.0/24) to IANA.  It also instructs IANA to restructure its
   IPv4 and IPv6 Special-Purpose Address Registries.  Upon
   restructuring, the aforementioned registries will record all special-
   purpose address blocks, maintaining a common set of information
   regarding each address block.

   This memo obsoletes RFCs 4773, 5156, 5735, and 5736.

Status of This Memo

   This memo documents an Internet Best Current Practice.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   BCPs is available in Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc6890.















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Copyright Notice

   Copyright (c) 2013 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Table of Contents

   1. Introduction ....................................................2
   2. IANA Considerations .............................................3
      2.1. Assignment of an IPv4 Address Block to IANA ................3
      2.2. Restructuring of the IPv4 and IPv6 Special-Purpose
           Address ....................................................4
           2.2.1. Information Requirements ............................4
           2.2.2. IPv4 Special-Purpose Address Registry Entries .......6
           2.2.3. IPv6 Special-Purpose Address Registry Entries ......14
   3. Security Considerations ........................................20
   4. Acknowledgements ...............................................20
   5. Informative References .........................................20

1.  Introduction

   In order to support new protocols and practices, the IETF
   occasionally reserves an address block for a special purpose.  For
   example, [RFC1122] reserves an IPv4 address block (0.0.0.0/8) to
   represent the local (i.e., "this") network.  Likewise, [RFC4291]
   reserves an IPv6 address block (fe80::/10) to represent link-scoped
   unicast addresses.

   Periodically, the IETF publishes an RFC that catalogs special-purpose
   address blocks.  Currently, [RFC5735] catalogs all IPv4 special-
   purpose address blocks and [RFC5156] catalogs all IPv6 special-
   purpose address blocks.

   [RFC5736] assigns an IPv4 address block (192.0.0.0/24) to IANA and
   instructs IANA to allocate special-purpose address blocks from this
   space.  [RFC5736] also instructs IANA to create an IPv4 Special-
   Purpose Address Registry that records allocations from this address




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   space.  However, [RFC5736] does not instruct IANA to record special-
   purpose address block reservations from outside of the aforementioned
   space in the IPv4 Special-Purpose Address Registry.

   Likewise, [RFC2928] assigns an IPv6 address block (2001:0000::/23) to
   IANA and instructs IANA to allocate special-purpose address blocks
   from this space.  [RFC4773] instructs IANA to create an IPv6 Special-
   Purpose Address Registry that records allocations from this address
   space.  However, [RFC4773] does not instruct IANA to record special-
   purpose address block reservations from outside of the aforementioned
   space in the IPv6 Special-Purpose Address Registry.

   This memo reiterates the assignment of an IPv4 address block
   (192.0.0.0/24) to IANA.  It also instructs IANA to restructure its
   IPv4 and IPv6 Special-Purpose Address Registries.  Specifically, this
   memo instructs IANA to record all special-purpose address blocks in
   the aforementioned registries.  These include, but are not limited
   to, IPv4 allocations from 192.0.0.0/24 and IPv6 allocations from
   2001:0000::/23.  Furthermore, this memo defines:

   o  a common set of information that the registries will maintain
      regarding each special-purpose address block

   o  a common set of requirements for future entries

   When the aforementioned registries include all special-purpose
   address blocks, [RFC5735] and [RFC5156] will become redundant with
   the registries.  Therefore, this memo obsoletes [RFC5735] and
   [RFC5156].  Because this memo reiterates the assignment of
   192.0.0.0/24 to IANA, and because it restructures the IPv4 Special-
   Purpose Address Registry, it obsoletes [RFC5736].  Finally, because
   this memo restructures the IPv6 Special-Purpose Address Registry, it
   obsoletes [RFC4773].

2.  IANA Considerations

2.1.  Assignment of an IPv4 Address Block to IANA

   Table 7 of this document records the assignment of an IPv4 address
   block (192.0.0.0/24) to IANA for IETF protocol assignments.  This
   address allocation to IANA is intended to support IETF protocol
   assignments.  A more general view of the roles of IANA with respect
   to address allocation functions is documented in Sections 4.1 and 4.3
   [RFC2860].

   IANA has designated special-purpose address blocks in compliance with
   [RFC2860].




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2.2.  Restructuring of the IPv4 and IPv6 Special-Purpose Address
      Registries

   IANA has restructured the following registries:

      o  IPv4 Special-Purpose Address Registry

      o  IPv6 Special-Purpose Address Registry

   The IPv4 Special-Purpose Address Registry records all IPv4 special-
   purpose address blocks.  These reservations include, but are not
   limited to, allocations from the 192.0.0.0/24 address block.
   Likewise, the IPv6 Special-Purpose Address Registry records all IPv6
   special-purpose address blocks.  These reservations include, but are
   not limited to, allocations from the 2001:0000::/23 address block.

   Section 2.2.1 of this document describes information that both
   registries will maintain for each entry.  Initially, IANA has
   populated the IPv4 Special-Purpose Address Registry with information
   taken from Section 2.2.2 of this document.  Likewise, IANA has
   populated the IPv6 Special-Purpose Address Registry with information
   taken from Section 2.2.3 of this document.

   IANA will update the aforementioned registries as requested in the
   "IANA Considerations" section of a document that has passed IETF
   Review [RFC5226].  The "IANA Considerations" section must include all
   of the information specified in Section 2.2.1 of this document.

2.2.1.  Information Requirements

   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.




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   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  Global - 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 "Global" must also be false.























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2.2.2.  IPv4 Special-Purpose Address Registry Entries

   Tables 1 though 16, below, represent entries with which IANA has
   initially populated the IPv4 Special-Purpose Address Registry.

              +----------------------+----------------------------+
              | Attribute            | Value                      |
              +----------------------+----------------------------+
              | Address Block        | 0.0.0.0/8                  |
              | Name                 | "This host on this network"|
              | RFC                  | [RFC1122], Section 3.2.1.3 |
              | Allocation Date      | September 1981             |
              | Termination Date     | N/A                        |
              | Source               | True                       |
              | Destination          | False                      |
              | Forwardable          | False                      |
              | Global               | False                      |
              | Reserved-by-Protocol | True                       |
              +----------------------+----------------------------+

                    Table 1: "This host on this network"

                    +----------------------+---------------+
                    | Attribute            | Value         |
                    +----------------------+---------------+
                    | Address Block        | 10.0.0.0/8    |
                    | Name                 | Private-Use   |
                    | RFC                  | [RFC1918]     |
                    | Allocation Date      | February 1996 |
                    | Termination Date     | N/A           |
                    | Source               | True          |
                    | Destination          | True          |
                    | Forwardable          | True          |
                    | Global               | False         |
                    | Reserved-by-Protocol | False         |
                    +----------------------+---------------+

                       Table 2: Private-Use Networks













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                 +----------------------+----------------------+
                 | Attribute            | Value                |
                 +----------------------+----------------------+
                 | Address Block        | 100.64.0.0/10        |
                 | Name                 | Shared Address Space |
                 | RFC                  | [RFC6598]            |
                 | Allocation Date      | April 2012           |
                 | Termination Date     | N/A                  |
                 | Source               | True                 |
                 | Destination          | True                 |
                 | Forwardable          | True                 |
                 | Global               | False                |
                 | Reserved-by-Protocol | False                |
                 +----------------------+----------------------+

                       Table 3: Shared Address Space

              +----------------------+----------------------------+
              | Attribute            | Value                      |
              +----------------------+----------------------------+
              | Address Block        | 127.0.0.0/8                |
              | Name                 | Loopback                   |
              | RFC                  | [RFC1122], Section 3.2.1.3 |
              | Allocation Date      | September 1981             |
              | Termination Date     | N/A                        |
              | Source               | False [1]                  |
              | Destination          | False [1]                  |
              | Forwardable          | False [1]                  |
              | Global               | False [1]                  |
              | Reserved-by-Protocol | True                       |
              +----------------------+----------------------------+

              [1] Several protocols have been granted exceptions to this
                  rule.  For examples, see [RFC4379] and [RFC5884].

                             Table 4: Loopback















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                    +----------------------+----------------+
                    | Attribute            | Value          |
                    +----------------------+----------------+
                    | Address Block        | 169.254.0.0/16 |
                    | Name                 | Link Local     |
                    | RFC                  | [RFC3927]      |
                    | Allocation Date      | May 2005       |
                    | Termination Date     | N/A            |
                    | Source               | True           |
                    | Destination          | True           |
                    | Forwardable          | False          |
                    | Global               | False          |
                    | Reserved-by-Protocol | True           |
                    +----------------------+----------------+

                            Table 5: Link Local

                    +----------------------+---------------+
                    | Attribute            | Value         |
                    +----------------------+---------------+
                    | Address Block        | 172.16.0.0/12 |
                    | Name                 | Private-Use   |
                    | RFC                  | [RFC1918]     |
                    | Allocation Date      | February 1996 |
                    | Termination Date     | N/A           |
                    | Source               | True          |
                    | Destination          | True          |
                    | Forwardable          | True          |
                    | Global               | False         |
                    | Reserved-by-Protocol | False         |
                    +----------------------+---------------+

                       Table 6: Private-Use Networks


















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            +----------------------+---------------------------------+
            | Attribute            | Value                           |
            +----------------------+---------------------------------+
            | Address Block        | 192.0.0.0/24 [2]                |
            | Name                 | IETF Protocol Assignments       |
            | RFC                  | Section 2.1 of this document    |
            | Allocation Date      | January 2010                    |
            | Termination Date     | N/A                             |
            | Source               | False                           |
            | Destination          | False                           |
            | Forwardable          | False                           |
            | Global               | False                           |
            | Reserved-by-Protocol | False                           |
            +----------------------+---------------------------------+

              [2] Not usable unless by virtue of a more specific
                  reservation.

                    Table 7: IETF Protocol Assignments

             +----------------------+--------------------------------+
             | Attribute            | Value                          |
             +----------------------+--------------------------------+
             | Address Block        | 192.0.0.0/29                   |
             | Name                 | DS-Lite                        |
             | RFC                  | [RFC6333]                      |
             | Allocation Date      | June 2011                      |
             | Termination Date     | N/A                            |
             | Source               | True                           |
             | Destination          | True                           |
             | Forwardable          | True                           |
             | Global               | False                          |
             | Reserved-by-Protocol | False                          |
             +----------------------+--------------------------------+

                             Table 8: DS-Lite















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              +----------------------+----------------------------+
              | Attribute            | Value                      |
              +----------------------+----------------------------+
              | Address Block        | 192.0.2.0/24               |
              | Name                 | Documentation (TEST-NET-1) |
              | RFC                  | [RFC5737]                  |
              | Allocation Date      | January 2010               |
              | Termination Date     | N/A                        |
              | Source               | False                      |
              | Destination          | False                      |
              | Forwardable          | False                      |
              | Global               | False                      |
              | Reserved-by-Protocol | False                      |
              +----------------------+----------------------------+

                            Table 9: TEST-NET-1

                  +----------------------+--------------------+
                  | Attribute            | Value              |
                  +----------------------+--------------------+
                  | Address Block        | 192.88.99.0/24     |
                  | Name                 | 6to4 Relay Anycast |
                  | RFC                  | [RFC3068]          |
                  | Allocation Date      | June 2001          |
                  | Termination Date     | N/A                |
                  | Source               | True               |
                  | Destination          | True               |
                  | Forwardable          | True               |
                  | Global               | True               |
                  | Reserved-by-Protocol | False              |
                  +----------------------+--------------------+

                       Table 10: 6to4 Relay Anycast


















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                    +----------------------+----------------+
                    | Attribute            | Value          |
                    +----------------------+----------------+
                    | Address Block        | 192.168.0.0/16 |
                    | Name                 | Private-Use    |
                    | RFC                  | [RFC1918]      |
                    | Allocation Date      | February 1996  |
                    | Termination Date     | N/A            |
                    | Source               | True           |
                    | Destination          | True           |
                    | Forwardable          | True           |
                    | Global               | False          |
                    | Reserved-by-Protocol | False          |
                    +----------------------+----------------+

                      Table 11: Private-Use Networks

                    +----------------------+---------------+
                    | Attribute            | Value         |
                    +----------------------+---------------+
                    | Address Block        | 198.18.0.0/15 |
                    | Name                 | Benchmarking  |
                    | RFC                  | [RFC2544]     |
                    | Allocation Date      | March 1999    |
                    | Termination Date     | N/A           |
                    | Source               | True          |
                    | Destination          | True          |
                    | Forwardable          | True          |
                    | Global               | False         |
                    | Reserved-by-Protocol | False         |
                    +----------------------+---------------+

          Table 12: Network Interconnect Device Benchmark Testing


















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              +----------------------+----------------------------+
              | Attribute            | Value                      |
              +----------------------+----------------------------+
              | Address Block        | 198.51.100.0/24            |
              | Name                 | Documentation (TEST-NET-2) |
              | RFC                  | [RFC5737]                  |
              | Allocation Date      | January 2010               |
              | Termination Date     | N/A                        |
              | Source               | False                      |
              | Destination          | False                      |
              | Forwardable          | False                      |
              | Global               | False                      |
              | Reserved-by-Protocol | False                      |
              +----------------------+----------------------------+

                           Table 13: TEST-NET-2

              +----------------------+----------------------------+
              | Attribute            | Value                      |
              +----------------------+----------------------------+
              | Address Block        | 203.0.113.0/24             |
              | Name                 | Documentation (TEST-NET-3) |
              | RFC                  | [RFC5737]                  |
              | Allocation Date      | January 2010               |
              | Termination Date     | N/A                        |
              | Source               | False                      |
              | Destination          | False                      |
              | Forwardable          | False                      |
              | Global               | False                      |
              | Reserved-by-Protocol | False                      |
              +----------------------+----------------------------+

                           Table 14: TEST-NET-3


















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                 +----------------------+----------------------+
                 | Attribute            | Value                |
                 +----------------------+----------------------+
                 | Address Block        | 240.0.0.0/4          |
                 | Name                 | Reserved             |
                 | RFC                  | [RFC1112], Section 4 |
                 | Allocation Date      | August 1989          |
                 | Termination Date     | N/A                  |
                 | Source               | False                |
                 | Destination          | False                |
                 | Forwardable          | False                |
                 | Global               | False                |
                 | Reserved-by-Protocol | True                 |
                 +----------------------+----------------------+

                     Table 15: Reserved for Future Use

                 +----------------------+----------------------+
                 | Attribute            | Value                |
                 +----------------------+----------------------+
                 | Address Block        | 255.255.255.255/32   |
                 | Name                 | Limited Broadcast    |
                 | RFC                  | [RFC0919], Section 7 |
                 | Allocation Date      | October 1984         |
                 | Termination Date     | N/A                  |
                 | Source               | False                |
                 | Destination          | True                 |
                 | Forwardable          | False                |
                 | Global               | False                |
                 | Reserved-by-Protocol | False                |
                 +----------------------+----------------------+

                        Table 16: Limited Broadcast


















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2.2.3.  IPv6 Special-Purpose Address Registry Entries

   Tables 17 through 28, below, represent entries with which the IANA
   has initially populated the IPv6 Special-Purpose Address Registry.

                   +----------------------+------------------+
                   | Attribute            | Value            |
                   +----------------------+------------------+
                   | Address Block        | ::1/128          |
                   | Name                 | Loopback Address |
                   | RFC                  | [RFC4291]        |
                   | Allocation Date      | February 2006    |
                   | Termination Date     | N/A              |
                   | Source               | False            |
                   | Destination          | False            |
                   | Forwardable          | False            |
                   | Global               | False            |
                   | Reserved-by-Protocol | True             |
                   +----------------------+------------------+

                        Table 17: Loopback Address

                 +----------------------+---------------------+
                 | Attribute            | Value               |
                 +----------------------+---------------------+
                 | Address Block        | ::/128              |
                 | Name                 | Unspecified Address |
                 | RFC                  | [RFC4291]           |
                 | Allocation Date      | February 2006       |
                 | Termination Date     | N/A                 |
                 | Source               | True                |
                 | Destination          | False               |
                 | Forwardable          | False               |
                 | Global               | False               |
                 | Reserved-by-Protocol | True                |
                 +----------------------+---------------------+

                       Table 18: Unspecified Address













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                +----------------------+---------------------+
                | Attribute            | Value               |
                +----------------------+---------------------+
                | Address Block        | 64:ff9b::/96        |
                | Name                 | IPv4-IPv6 Translat. |
                | RFC                  | [RFC6052]           |
                | Allocation Date      | October 2010        |
                | Termination Date     | N/A                 |
                | Source               | True                |
                | Destination          | True                |
                | Forwardable          | True                |
                | Global               | True                |
                | Reserved-by-Protocol | False               |
                +----------------------+---------------------+

                  Table 19: IPv4-IPv6 Translation Address

                 +----------------------+---------------------+
                 | Attribute            | Value               |
                 +----------------------+---------------------+
                 | Address Block        | ::ffff:0:0/96       |
                 | Name                 | IPv4-mapped Address |
                 | RFC                  | [RFC4291]           |
                 | Allocation Date      | February 2006       |
                 | Termination Date     | N/A                 |
                 | Source               | False               |
                 | Destination          | False               |
                 | Forwardable          | False               |
                 | Global               | False               |
                 | Reserved-by-Protocol | True                |
                 +----------------------+---------------------+

                       Table 20: IPv4-Mapped Address


















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              +----------------------+----------------------------+
              | Attribute            | Value                      |
              +----------------------+----------------------------+
              | Address Block        | 100::/64                   |
              | Name                 | Discard-Only Address Block |
              | RFC                  | [RFC6666]                  |
              | Allocation Date      | June 2012                  |
              | Termination Date     | N/A                        |
              | Source               | True                       |
              | Destination          | True                       |
              | Forwardable          | True                       |
              | Global               | False                      |
              | Reserved-by-Protocol | False                      |
              +----------------------+----------------------------+

                       Table 21: Discard-Only Prefix

              +----------------------+---------------------------+
              | Attribute            | Value                     |
              +----------------------+---------------------------+
              | Address Block        | 2001::/23                 |
              | Name                 | IETF Protocol Assignments |
              | RFC                  | [RFC2928]                 |
              | Allocation Date      | September 2000            |
              | Termination Date     | N/A                       |
              | Source               | False[1]                  |
              | Destination          | False[1]                  |
              | Forwardable          | False[1]                  |
              | Global               | False[1]                  |
              | Reserved-by-Protocol | False                     |
              +----------------------+---------------------------+

             [1] Unless allowed by a more specific allocation.

                    Table 22: IETF Protocol Assignments
















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                    +----------------------+----------------+
                    | Attribute            | Value          |
                    +----------------------+----------------+
                    | Address Block        | 2001::/32      |
                    | Name                 | TEREDO         |
                    | RFC                  | [RFC4380]      |
                    | Allocation Date      | January 2006   |
                    | Termination Date     | N/A            |
                    | Source               | True           |
                    | Destination          | True           |
                    | Forwardable          | True           |
                    | Global               | False          |
                    | Reserved-by-Protocol | False          |
                    +----------------------+----------------+

                             Table 23: TEREDO

                    +----------------------+----------------+
                    | Attribute            | Value          |
                    +----------------------+----------------+
                    | Address Block        | 2001:2::/48    |
                    | Name                 | Benchmarking   |
                    | RFC                  | [RFC5180]      |
                    | Allocation Date      | April 2008     |
                    | Termination Date     | N/A            |
                    | Source               | True           |
                    | Destination          | True           |
                    | Forwardable          | True           |
                    | Global               | False          |
                    | Reserved-by-Protocol | False          |
                    +----------------------+----------------+

                          Table 24: Benchmarking


















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                    +----------------------+---------------+
                    | Attribute            | Value         |
                    +----------------------+---------------+
                    | Address Block        | 2001:db8::/32 |
                    | Name                 | Documentation |
                    | RFC                  | [RFC3849]     |
                    | Allocation Date      | July 2004     |
                    | Termination Date     | N/A           |
                    | Source               | False         |
                    | Destination          | False         |
                    | Forwardable          | False         |
                    | Global               | False         |
                    | Reserved-by-Protocol | False         |
                    +----------------------+---------------+

                          Table 25: Documentation

                     +----------------------+--------------+
                     | Attribute            | Value        |
                     +----------------------+--------------+
                     | Address Block        | 2001:10::/28 |
                     | Name                 | ORCHID       |
                     | RFC                  | [RFC4843]    |
                     | Allocation Date      | March 2007   |
                     | Termination Date     | March 2014   |
                     | Source               | False        |
                     | Destination          | False        |
                     | Forwardable          | False        |
                     | Global               | False        |
                     | Reserved-by-Protocol | False        |
                     +----------------------+--------------+

                             Table 26: ORCHID


















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                    +----------------------+---------------+
                    | Attribute            | Value         |
                    +----------------------+---------------+
                    | Address Block        | 2002::/16 [2] |
                    | Name                 | 6to4          |
                    | RFC                  | [RFC3056]     |
                    | Allocation Date      | February 2001 |
                    | Termination Date     | N/A           |
                    | Source               | True          |
                    | Destination          | True          |
                    | Forwardable          | True          |
                    | Global               | N/A [2]       |
                    | Reserved-by-Protocol | False         |
                    +----------------------+---------------+

                      [2] See [RFC3056] for details.

                              Table 27: 6to4

                     +----------------------+--------------+
                     | Attribute            | Value        |
                     +----------------------+--------------+
                     | Address Block        | fc00::/7     |
                     | Name                 | Unique-Local |
                     | RFC                  | [RFC4193]    |
                     | Allocation Date      | October 2005 |
                     | Termination Date     | N/A          |
                     | Source               | True         |
                     | Destination          | True         |
                     | Forwardable          | True         |
                     | Global               | False        |
                     | Reserved-by-Protocol | False        |
                     +----------------------+--------------+

                          Table 28: Unique-Local
















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                +----------------------+-----------------------+
                | Attribute            | Value                 |
                +----------------------+-----------------------+
                | Address Block        | fe80::/10             |
                | Name                 | Linked-Scoped Unicast |
                | RFC                  | [RFC4291]             |
                | Allocation Date      | February 2006         |
                | Termination Date     | N/A                   |
                | Source               | True                  |
                | Destination          | True                  |
                | Forwardable          | False                 |
                | Global               | False                 |
                | Reserved-by-Protocol | True                  |
                +----------------------+-----------------------+

                      Table 29: Linked-Scoped Unicast

3.  Security Considerations

   Security of the Internet's routing system relies on the ability to
   authenticate an assertion of unique control of an address block.
   Measures to authenticate such assertions rely on validation that the
   address block forms part of an existing allocated address block and
   that there is a trustable and unique reference in the IANA address
   registries.

   The proposed registry is intended to provide an authoritative source
   of information regarding the currency and intended purpose of special
   purpose address blocks that are designated from the IANA-administered
   Special-Purpose registry.  This is a small step towards the creation
   of a comprehensive registry framework that can be used as a trust
   point for commencing a chain of address validation.  Consideration
   should be given to IANA registry publication formats that are machine
   parsable.  Additionally, consideration should be given to the use of
   file signatures and associated certificate mechanisms to allow
   applications to confirm that the registry contents are current and
   that they have been published by the IANA.

4.  Acknowledgements

   The authors thank Geoff Huston and Randy Bush for their helpful
   comments.  The authors also express their gratitude to an anonymous
   donor, without whom this document would not have been written.

5.  Informative References

   [RFC0919]  Mogul, J., "Broadcasting Internet Datagrams", STD 5, RFC
              919, October 1984.



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RFC 6890           Special-Purpose Address Registries         April 2013


   [RFC1112]  Deering, S., "Host extensions for IP multicasting", STD 5,
              RFC 1112, August 1989.

   [RFC1122]  Braden, R., Ed., "Requirements for Internet Hosts -
              Communication Layers", STD 3, RFC 1122, October 1989.

   [RFC1918]  Rekhter, Y., Moskowitz, B., Karrenberg, D., de Groot, G.,
              and E. Lear, "Address Allocation for Private Internets",
              BCP 5, RFC 1918, February 1996.

   [RFC2544]  Bradner, S. and J. McQuaid, "Benchmarking Methodology for
              Network Interconnect Devices", RFC 2544, March 1999.

   [RFC2860]  Carpenter, B., Baker, F., and M. Roberts, "Memorandum of
              Understanding Concerning the Technical Work of the
              Internet Assigned Numbers Authority", RFC 2860, June 2000.

   [RFC2928]  Hinden, R., Deering, S., Fink, R., and T. Hain, "Initial
              IPv6 Sub-TLA ID Assignments", RFC 2928, September 2000.

   [RFC3056]  Carpenter, B. and K. Moore, "Connection of IPv6 Domains
              via IPv4 Clouds", RFC 3056, February 2001.

   [RFC3068]  Huitema, C., "An Anycast Prefix for 6to4 Relay Routers",
              RFC 3068, June 2001.

   [RFC3849]  Huston, G., Lord, A., and P. Smith, "IPv6 Address Prefix
              Reserved for Documentation", RFC 3849, July 2004.

   [RFC3927]  Cheshire, S., Aboba, B., and E. Guttman, "Dynamic
              Configuration of IPv4 Link-Local Addresses", RFC 3927, May
              2005.

   [RFC4193]  Hinden, R. and B. Haberman, "Unique Local IPv6 Unicast
              Addresses", RFC 4193, October 2005.

   [RFC4291]  Hinden, R. and S. Deering, "IP Version 6 Addressing
              Architecture", RFC 4291, February 2006.

   [RFC4379]  Kompella, K. and G. Swallow, "Detecting Multi-Protocol
              Label Switched (MPLS) Data Plane Failures", RFC 4379,
              February 2006.

   [RFC4380]  Huitema, C., "Teredo: Tunneling IPv6 over UDP through
              Network Address Translations (NATs)", RFC 4380, February
              2006.





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RFC 6890           Special-Purpose Address Registries         April 2013


   [RFC4773]  Huston, G., "Administration of the IANA Special Purpose
              IPv6 Address Block", RFC 4773, December 2006.

   [RFC4843]  Nikander, P., Laganier, J., and F. Dupont, "An IPv6 Prefix
              for Overlay Routable Cryptographic Hash Identifiers
              (ORCHID)", RFC 4843, April 2007.

   [RFC5156]  Blanchet, M., "Special-Use IPv6 Addresses", RFC 5156,
              April 2008.

   [RFC5180]  Popoviciu, C., Hamza, A., Van de Velde, G., and D.
              Dugatkin, "IPv6 Benchmarking Methodology for Network
              Interconnect Devices", RFC 5180, May 2008.

   [RFC5226]  Narten, T. and H. Alvestrand, "Guidelines for Writing an
              IANA Considerations Section in RFCs", BCP 26, RFC 5226,
              May 2008.

   [RFC5735]  Cotton, M. and L. Vegoda, "Special Use IPv4 Addresses",
              RFC 5735, January 2010.

   [RFC5736]  Huston, G., Cotton, M., and L. Vegoda, "IANA IPv4 Special
              Purpose Address Registry", RFC 5736, January 2010.

   [RFC5737]  Arkko, J., Cotton, M., and L. Vegoda, "IPv4 Address Blocks
              Reserved for Documentation", RFC 5737, January 2010.

   [RFC5884]  Aggarwal, R., Kompella, K., Nadeau, T., and G. Swallow,
              "Bidirectional Forwarding Detection (BFD) for MPLS Label
              Switched Paths (LSPs)", RFC 5884, June 2010.

   [RFC6052]  Bao, C., Huitema, C., Bagnulo, M., Boucadair, M., and X.
              Li, "IPv6 Addressing of IPv4/IPv6 Translators", RFC 6052,
              October 2010.

   [RFC6333]  Durand, A., Droms, R., Woodyatt, J., and Y. Lee, "Dual-
              Stack Lite Broadband Deployments Following IPv4
              Exhaustion", RFC 6333, August 2011.

   [RFC6598]  Weil, J., Kuarsingh, V., Donley, C., Liljenstolpe, C., and
              M. Azinger, "IANA-Reserved IPv4 Prefix for Shared Address
              Space", BCP 153, RFC 6598, April 2012.

   [RFC6666]  Hilliard, N. and D. Freedman, "A Discard Prefix for IPv6",
              RFC 6666, August 2012.






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Authors' Addresses

   Michelle Cotton
   Internet Corporation for Assigned Names and Numbers (ICANN)
   12025 Waterfront Drive, Suite 300
   Los Angeles, CA 90094-2536
   USA

   Phone: +310-823-9358
   EMail: michelle.cotton@icann.org
   URI:   http://www.icann.org/


   Leo Vegoda
   Internet Corporation for Assigned Names and Numbers (ICANN)
   12025 Waterfront Drive, Suite 300
   Los Angeles, CA 90094-2536
   USA

   Phone: +310-823-9358
   EMail: leo.vegoda@icann.org
   URI:   http://www.icann.org/


   Ronald P Bonica (editor)
   Juniper Networks
   2251 Corporate Park Drive
   Herndon, VA 20171
   USA

   EMail: rbonica@juniper.net


   Brian Haberman
   Johns Hopkins University (JHU) Applied Physics Lab
   11100 Johns Hopkins Road
   Laurel, MD 20723-6099
   USA

   EMail: brian@innovationslab.net











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