RFC 2770

RFC 2770: GLOP Addressing in 233/8 🎀

Okay bestie, this one is an Experimental RFC from February 2000 🧪✨. David Meyer (Cisco Systems) and Peter Lothberg (Sprint) wrote it, and it doesn't list anything it obsoletes or updates. It's giving "let's try something and see" energy 💅

Status of This Memo 📣

This memo defines an Experimental Protocol for the Internet community. It does not specify an Internet standard of any kind. Discussion and suggestions for improvement are requested. Distribution of this memo is unlimited. 🦋

Copyright Notice ©️

Copyright (C) The Internet Society (2000). All Rights Reserved. 💜

Abstract 🌸

So this describes an experimental policy for using the class D address space. The experimental statically assigned subset is 233/8 🌈 This new experimental allocation is in addition to the ones listed on [IANA] (e.g. [RFC2365]).

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. 💌

1. Problem Statement 🔥

Okay so multicast addresses have traditionally been handed out by a dynamic mechanism like SDR [SAP]. But lowkey, a lot of current multicast deployment models don't vibe with dynamic allocation 😩 For example, many content aggregators need group addresses that stay fixed for a timescale that doesn't work with a mechanism like the one described in [SAP]. Even more concerning, since providers, content aggregators, and application writers don't have general consensus on an allocation mechanism, the Internet is left without a coherent multicast address allocation scheme 💀

The MALLOC working group is looking at a specific strategy for global multicast address allocation [MADCAP, MASC]. This experiment will run in parallel with that work. MADCAP may be employed within AS's, if so desired. 🧚

So this document proposes an experimental method of statically allocating multicast addresses with global scope. The experiment will last for one year, but it may be extended as described in section 6 🎀

2. Address Space 🍓

For the purposes of this experiment, the IANA has allocated 233/8. The remaining 24 bits will be administered in a manner similar to that described in RFC 1797:

    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   |
   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

2.1. Example ✨

Let's do an example, bestie 🫶 Take AS 5662. Written in binary and left padded with 0s, it becomes 0001011000011110. Map the high order octet to the second octet of the address, and the low order octet to the third octet, and you get 233.22.30/24 🔥

3. Allocation 💖

As mentioned above, the allocation proposed here follows the RFC 1797 (case 1) allocation scheme, with a few changes: 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 RFC 1797, using the AS number this way lets the experiment get underway quickly. It automatically allocates some addresses to each service provider and does not require a registration step 🦋

3.1. Private AS Space 🙈

The address space mapped to the private AS space [RFC1930] is reserved for future allocation.

4. Transition from GLOP to Other Address Allocation Schemes 🌈

It may not be necessary to transition from the address allocation scheme described here to a more dynamic approach (see, e.g., [MASC]). The reasoning is that the statically assigned addresses taken from 233/8 may be sufficient for applications that must have static addressing. Any other addressing can come from a dynamic mechanism such as [MASC], the administratively scoped address space [RFC2365], or the Single-source address space [SS] ✨

5. Security Considerations 🔒

The approach described here may have the effect of reducing 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. 🛡️

6. IANA Considerations 📋

IANA has allocated 233/8 for experimental assignments. This assignment should time out one year after the assignment is made. The assignment may be renewed at that time. It should be noted that the experiment described here is in the same spirit as the experiment described in [RFC1797] 🌸

7. Acknowledgments 🫶

This idea originated with Peter Lothberg's idea that we use the same allocation (AS based) as described in RFC 1797, but in the class D address space. Randy Bush and Mark Handley contributed many insightful comments. Thank you, legends 👑

8. References 📚

• [RFC2730] Hanna, S., Patel, B. and M. Shah, "Multicast Address Dynamic Client Allocation Protocol (MADCAP)", RFC 2730, December 1999.
• [MASC] D. Estrin, et al., "The Multicast Address-Set Claim (MASC) Protocol", Work in Progress.
• [MSDP] D. Farinacci et al., "Multicast Source Discovery Protocol (MSDP)", Work in Progress.
• [IANA] www.isi.edu/in-notes/iana/assignments/multicast-addresses
• [RFC1797] IANA, "Class A Subnet Experiment", RFC 1797, April 1995.
• [RFC1930] Hawkinson, J. and T. Bates, "Guidelines for creation, selection, and registration of an Autonomous System (AS)", RFC 1930, March 1996.
• [RFC2365] Meyer, D., "Administratively Scoped IP Multicast", RFC 2365, July 1998.
• [RFC2374] Hinden, R., O'Dell, M. and S. Deering, "An IPv6 Aggregatable Global Unicast Address Format", RFC 2374, July 1998.
• [SAP] Handley, M., "SAP: Session Announcement Protocol", Work in Progress.
• [SS] www.isi.edu/in-notes/iana/assignments/single-source-multicast

9. Authors' Addresses 🏡

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

10. Full Copyright Statement 💅

Copyright (C) The Internet Society (2000). 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. 🎀