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RFC 5737

Updates RFC 1166

Internet Engineering Task Force (IETF)                          J. Arkko
Request for Comments: 5737                                      Ericsson
Updates: 1166                                                  M. Cotton
Category: Informational                                        L. Vegoda
ISSN: 2070-1721                                                    ICANN
                                                            January 2010

             IPv4 Address Blocks Reserved for Documentation


   Three IPv4 unicast address blocks are reserved for use in examples in
   specifications and other documents.  This document describes the use
   of these blocks.

Status of This Memo

   This document is not an Internet Standards Track specification; it is
   published for informational purposes.

   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).  Not all documents
   approved by the IESG are a candidate for any level of Internet
   Standard; see 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

Copyright Notice

   Copyright (c) 2010 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
   ( 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.

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RFC 5737                     IPv4 Examples                  January 2010

1.  Introduction

   This document describes three IPv4 address blocks that are provided
   for use in documentation.  The use of designated address ranges for
   documentation and examples reduces the likelihood of conflicts and
   confusion arising from the use of addresses assigned for some other

   [RFC1166] reserves the first of the three address blocks,  The other two address blocks have recently been
   allocated for this purpose, primarily to ease the writing of examples
   involving addresses from multiple networks.

   Other documentation ranges have been defined in the IETF, including
   the IPv6 documentation prefix [RFC3849] and example domain names
   [RFC2606].  Documentation also makes use of the ranges reserved in

2.  Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   document are to be interpreted as described in BCP 14, [RFC2119].

3.  Documentation Address Blocks

   The blocks (TEST-NET-1), (TEST-NET-2),
   and (TEST-NET-3) are provided for use in

4.  Operational Implications

   Addresses within the TEST-NET-1, TEST-NET-2, and TEST-NET-3 blocks
   SHOULD NOT appear on the public Internet and are used without any
   coordination with IANA or an Internet registry [RFC2050].  Network
   operators SHOULD add these address blocks to the list of non-
   routeable address spaces, and if packet filters are deployed, then
   this address block SHOULD be added to packet filters.

   These blocks are not for local use, and the filters may be used in
   both local and public contexts.

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RFC 5737                     IPv4 Examples                  January 2010

5.  The Status of

   Note that has been used for some examples in the past.
   However, this block did not appear in the list of special prefixes in
   [RFC3330] or its successors, and the block is therefore not reserved
   for any special purpose.  The block can be used for regular address
   assignments with caution.

6.  Security Considerations

   This document has no security implications.

7.  IANA Considerations

   IANA has recorded the allocation of the three address blocks in the
   IPv4 address registry.  No end party is to be assigned these

8.  References

8.1.  Normative References

   [RFC2119]  Bradner, S., "Key words for use in RFCs to Indicate
              Requirement Levels", BCP 14, RFC 2119, March 1997.

8.2.  Informative References

   [RFC1166]  Kirkpatrick, S., Stahl, M., and M. Recker, "Internet
              numbers", RFC 1166, July 1990.

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

   [RFC2050]  Hubbard, K., Kosters, M., Conrad, D., Karrenberg, D., and
              BCP 12, RFC 2050, November 1996.

   [RFC2606]  Eastlake, D. and A. Panitz, "Reserved Top Level DNS
              Names", BCP 32, RFC 2606, June 1999.

   [RFC3330]  IANA, "Special-Use IPv4 Addresses", RFC 3330,
              September 2002.

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

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RFC 5737                     IPv4 Examples                  January 2010

Appendix A.  Acknowledgments

   The authors would like to offer a special note of thanks to APNIC,
   which nominated and for this purpose.
   The authors would also like to acknowledge that this document
   inherits material from [RFC3849].

   The authors would also like to thank Geoff Huston, Peter Koch, Ulf
   Olsson, John Klensin, and others for interesting discussions of this

Authors' Addresses

   Jari Arkko
   Jorvas  02420


   Michelle Cotton
   Internet Corporation for Assigned Names and Numbers
   4676 Admiralty Way, Suite 330
   Marina del Rey  90292
   United States of America

   Phone: +1-310-823-9358

   Leo Vegoda
   Internet Corporation for Assigned Names and Numbers
   4676 Admiralty Way, Suite 330
   Marina del Rey  90292
   United States of America

   Phone: +1-310-823-9358

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