Network Working Group D. Meyer Request for Comments: 3138 Sprint Category: Informational June 2001 Extended Assignments in 233/8 Status 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. Introduction RFC 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 on RFC 2770 to allow routing registries to assign multicast addresses from the GLOP space corresponding to the RFC 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 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 in RFC 2119 [RFC2119]. Meyer Informational [Page 1] RFC 3138 Extended Assignments in 233/8 June 2001 2. Overview http://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.net Meyer Informational [Page 2] RFC 3138 Extended Assignments in 233/8 June 2001 7. 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 2001 Full 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]