MBONED Working Group David Meyer Internet Draft Cisco Systems Peter Lothberg Sprint Category Experimental draft-ietf-malloc-static-allocation-01.txt April, 1999 Static Allocations in 233/8 1. Status of this Memo This document is an Internet-Draft and is in full conformance with all provisions of Section 10 of RFC 2026. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF), its areas, and its working groups. Note that other groups may also distribute working documents as Internet- Drafts. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet- Drafts as reference material or to cite them other than as "work in progress." The list of current Internet-Drafts can be accessed at http://www.ietf.org/ietf/1id-abstracts.txt. The list of Internet-Draft Shadow Directories can be accessed at http://www.ietf.org/shadow.html. 2. Abstract This describes an experimental policy for use of the class D address space using 233/8 as the experimental statically assigned subset of the class D address space. This new experimental allocation is in addition to those described on [IANA] (e.g. [RFC2365]). This memo is a product of the Multicast-Address Allocation working group (MALLOC) in the Internet and Transport Areas of the Internet Engineering Task Force. Submit comments to or the authors. David Meyer [Page 1] Internet Draft draft-ietf-malloc-static-allocation-01.txt April, 1999 3. Copyright Notice Copyright (C) The Internet Society (1999). All Rights Reserved. 4. Problem Statement Multicast addresses have traditionally been allocated by a dynamic mechanism such as SDR [SAP]. However, many current multicast deployment models are not amenable to dynamic allocation. For example, many content aggregators require group addresses which are fixed on a time scale which is not amenable to allocation by a mechanism such as described in [SAP]. Perhaps more seriously, since there isn't general consensus by providers, content aggregators, or application writers as to the allocation mechanism, the Internet is left without a coherent multicast address allocation scheme. While the MALLOC working group is looking at a specific strategy [MADCAP, MASC], it is proposed that a different strategy be developed in parallel. 5. Address Space For purposes of the experiment described here, the IANA should allocate 233/8. The remaining 24 bits will be administered in a manner similar to that described in RFC1797: 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | 233 | 16 bits AS | local bits | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ 5.1. Example Consider, for example, AS 5662. Written in binary, left padded with 0s, we get 0001011000011110. Mapping the high order octet to the second octet of the address, and the low order octet to the third octet, we get 233.22.30/24. David Meyer [Page 2] Internet Draft draft-ietf-malloc-static-allocation-01.txt April, 1999 6. Allocation As mentioned above, the allocation proposed here follows the RFC1797 (case 1) allocation scheme, modified as follows: the high order octet has the value 233, and the next 16 bits are a previously assigned Autonomous System number (AS), as registered by a network registry and listed in the RWhois database system. This allows a single /24 per AS. As was the case with RFC1797, using the AS number in this way allows the experiment to get underway quickly in that it automatically allocates some addresses to each service provider and does not require a registration step. 6.1. Private AS Space The address space mapped to the private AS space (as defined in [RFC1930], is reserved for future allocation. 7. Security Considerations The approach described here may have the effect of reduced exposure to denial of space attacks based on dynamic allocation. Further, since dynamic assignment does not cross domain boundaries, well known intra-domain security techniques can be applied. 8. IANA Considerations IANA should allocate 233/8 for experimental assignments. This assigment should timeout one year after the assigment is made. The assignment may be renewed at that time. It should be noted that the experiment described here is in the same spirit the experiment described in [RFC1797]. David Meyer [Page 3] Internet Draft draft-ietf-malloc-static-allocation-01.txt April, 1999 9. Acknowledgments This idea originated with Peter Lothberg's idea that we use the same allocation (AS based) as described in RFC 1797 in the class D address space. Randy Bush and Mark Handley contributed many insightful comments. 10. References [MADCAP] B. Patel, et. al., "Multicast Address Dynamic Client Allocation Protocol (MADCAP)", draft-ietf-malloc-madcap-04.txt, Feburay, 1999. [MASC] D. Estrin, et. al., "The Multicast Address-Set Claim (MASC) Protocol", draft-ietf-malloc-masc-01.txt, August, 1998. [IANA] www.isi.edu/in-notes/iana/assignments/multicast-addresses [RFC1797] IANA, "Class A Subnet Experiment", RFC 1797, April, 1995. [RFC1930] J. Hawkinson, et. al., "Guidelines for creation, selection, and registration of an Autonomous System (AS)", RFC1930, March, 1996. [RFC2365] David Meyer, "Administratively Scoped IP Multicast", July, 1998. [RFC2374] R. Hinden, et. al., "An IPv6 Aggregatable Global Unicast Address Format", July, 1998. [SAP] Handley, Mark, "SAP: Session Announcement Protocol", draft-ietf-mmusic-sap-00.txt, November, 1996. David Meyer [Page 4] Internet Draft draft-ietf-malloc-static-allocation-01.txt April, 1999 11. Author's Address David Meyer Cisco Systems, Inc. 170 W. Tasman Drive San Jose, CA 95134-1706 United States EMail: dmm@cisco.com Peter Lothberg Sprint VARESA0104 12502 Sunrise Valley Drive Reston VA, 20196 Email: roll@sprint.net David Meyer [Page 5]