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Network Working Group                                           D. MeyerRequest for Comments: 3138                                        SprintCategory: Informational                                        June 2001Extended Assignments in 233/8Status of this Memo   This memo provides information for the Internet community.  It does   not specify an Internet standard of any kind.  Distribution of this   memo is unlimited.Copyright Notice   Copyright (C) The Internet Society (2001).  All Rights Reserved.Abstract   This memo provides describes the mapping of the GLOP addresses   corresponding to the private AS space.1. IntroductionRFC 2770 [RFC2770] describes an experimental policy for use of the   class D address space using 233/8.  The technique described there   maps 16 bits of Autonomous System number (AS) into the middle two   octets of 233/8 to yield a /24.  While this technique has been   successful, the assignments are inefficient in those cases in which a   /24 is too small or the user doesn't have its own AS.RFC 1930 [RFC1930] defines the private AS space to be 64512 through   65535.  This memo expands onRFC 2770 to allow routing registries to   assign multicast addresses from the GLOP space corresponding to theRFC 1930 private AS space.  This space will be referred to as the   EGLOP (Extended GLOP) address space.   This memo is a product of the Multicast Deployment Working Group   (MBONED) in the Operations and Management Area of the Internet   Engineering Task Force.  Submit comments to <mboned@ns.uoregon.edu>   or the authors.   The terms "Specification Required", "Expert Review", "IESG Approval",   "IETF Consensus", and "Standards Action", are used in this memo to   refer to the processes described in [RFC2434].  The keywords MUST,   MUST NOT, MAY, OPTIONAL, REQUIRED, RECOMMENDED, SHALL, SHALL NOT,   SHOULD, SHOULD NOT are to be interpreted as defined inRFC 2119   [RFC2119].Meyer                        Informational                      [Page 1]

RFC 3138             Extended Assignments in 233/8             June 20012. Overviewhttp://www.iana.org/assignments/multicast-addresses defines a   mechanism for assignment of multicast addresses that are generally   for use in network control applications.  It is envisioned that those   addresses assigned from the EGLOP space (233.252.0.0 -   233.255.255.255) will be used by applications that cannot use   Administratively Scoped Addressing [RFC2365], GLOP Addressing   [RFC2770], or Source Specific Multicast (Source Specific Multicast,   or SSM, is an extension of IP Multicast in which traffic is forwarded   to receivers from only those multicast sources for which the   receivers have explicitly expressed interest, and is primarily   targeted at one-to-many (broadcast) applications).3. Assignment Criteria   Globally scoped IPv4 multicast addresses in the EGLOP space are   assigned by a Regional Registry (RIR).  An applicant MUST, as per   [IANA], show that the request cannot be satisfied using   Administratively Scoped addressing [RFC2365], GLOP addressing   [RFC2770], or SSM.  The fine-grained assignment policy is left to the   assigning RIR.4. Security Considerations   The assignment scheme described in this document does not effect the   security properties of the the single source or any source multicast   service models.5. Acknowledgments   Kurt Kayser, Mirjam Kuehne, Michelle Schipper and Randy Bush provided   many insightful comments on earlier versions of this document.6. Author's Address   David Meyer   Sprint   12502 Sunrise Valley Dr   Reston VA,  20191   EMail: dmm@sprint.netMeyer                        Informational                      [Page 2]

RFC 3138             Extended Assignments in 233/8             June 20017. References   [IANA]http://www.iana.org/assignments/multicast-addresses   [RFC1930]       Hawkinson J. and T. Bates, "Guidelines for                   creation, selection, and registration of an                   Autonomous System (AS)",RFC 1930, March 1996.   [RFC2026]       Bradner, S., "The Internet Standards Process --                   Revision 3",BCP 9,RFC 2026, October 1996.   [RFC2119]       Bradner, S., "Key words for use in RFCs to                   Indicate Requirement Levels",BCP 14,RFC 2119,                   March 1997.   [RFC2365]       Meyer, D., "Administratively Scoped IP Multicast",RFC 2365, July 1998.   [RFC2770]       Meyer, D. and P. Lothberg, "GLOP Addressing in                   233/8",RFC 2770, February 2000.   [RFC2780]       Bradner, S. and V. Paxson, "IANA Allocation                   Guidelines For Values In the Internet Protocol                   and Related Headers",BCP 37,RFC 2780, March                   2000.Meyer                        Informational                      [Page 3]

RFC 3138             Extended Assignments in 233/8             June 2001Full Copyright Statement   Copyright (C) The Internet Society (2001).  All Rights Reserved.   This document and translations of it may be copied and furnished to   others, and derivative works that comment on or otherwise explain it   or assist in its implementation may be prepared, copied, published   and distributed, in whole or in part, without restriction of any   kind, provided that the above copyright notice and this paragraph are   included on all such copies and derivative works.  However, this   document itself may not be modified in any way, such as by removing   the copyright notice or references to the Internet Society or other   Internet organizations, except as needed for the purpose of   developing Internet standards in which case the procedures for   copyrights defined in the Internet Standards process must be   followed, or as required to translate it into languages other than   English.   The limited permissions granted above are perpetual and will not be   revoked by the Internet Society or its successors or assigns.   This document and the information contained herein is provided on an   "AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING   TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING   BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION   HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.Acknowledgement   Funding for the RFC Editor function is currently provided by the   Internet Society.Meyer                        Informational                      [Page 4]