• 软件测试技术
  • 软件测试博客
  • 软件测试视频
  • 开源软件测试技术
  • 软件测试论坛
  • 软件测试沙龙
  • 软件测试资料下载
  • 软件测试杂志
  • 软件测试人才招聘
    暂时没有公告

字号: | 推荐给好友 上一篇 | 下一篇

RFC3180 - GLOP Addressing in 233/8

发布: 2007-6-23 14:09 | 作者:   | 来源:   | 查看: 34次 | 进入软件测试论坛讨论

领测软件测试网

   
  Network Working Group D. Meyer
Request for Comments: 3180 P. Lothberg
Obsoletes: 2770 Sprint
BCP: 53 September 2001
Category: Best Current Practice

GLOP Addressing in 233/8

Status of this Memo

This document specifies an Internet Best Current Practices for the
Internet Community, and requests discussion and suggestions for
improvements. Distribution of this memo is unlimited.

Copyright Notice

Copyright (C) The Internet Society (2001). All Rights Reserved.

Abstract

This document defines the policy for the use of 233/8 for statically
assigned multicast addresses.

1. Introduction

It is envisioned that the primary use of this space will be many-to-
many applications. This allocation is in addition to those described
on [IANA] (e.g., [RFC2365]). The IANA has allocated 223/8 as per RFC
2770 [RFC2770]. This document obsoletes RFC2770.

2. Problem Statement

Multicast addresses have traditionally been allocated by a dynamic
mechanism such as SDR [RFC2974]. However, many current multicast
deployment models are not amenable to dynamic allocation. For
example, many content aggregators require group addresses that are
fixed on a time scale that is not amenable to allocation by a
mechanism such as described in [RFC2974]. Perhaps more seriously,
since there is not 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.

The MALLOC working group has created a specific strategy for global
multicast address allocation [RFC2730, RFC2909]. However, this
approach has not been widely implemented or deployed. This document
proposes a solution for a subset of the problem, namely, those cases
not covered by Source Specific Multicast.

3. Address Space

The IANA has allocated 223/8 as per RFC2770 [RFC2770]. RFC2770
describes the administration of the middle two octets of 233/8 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 |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

3.1. 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.

4. 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
automatic assignment of a single /24 to each service provider and
does not require an additional registration step.

4.1. Private AS Space

The part of 233/8 that is mapped to the private AS space [RFC1930] is
assigned to the IRRs [RFC3138].

5. Large AS Numbers

It is important to note that this approach will work only for two
octet AS numbers. In particular, it does not work for any AS number
extension scheme.

6. Security Considerations

The approach described here may have the effect of reduced exposure
to denial-of-service attacks based on dynamic allocation. Further,
since dynamic assignment does not cross domain boundaries, well-known
intra-domain security techniques can be applied.

7. IANA Considerations

The IANA has assigned 233/8 for this purpose.

8. Acknowledgments

This proposal originated with Peter Lothberg's idea that we use the
same allocation (AS based) as described in RFC1797. Randy Bush and
Mark Handley contributed many insightful comments, and Pete and
Natalie Whiting contributed greatly to the readability of this
document.

9. References

[IANA] http://www.iana.org/numbers.html

[RFC1797] IANA, "Class A Subnet Experiment", RFC1797, April 1995.

[RFC1930] Hawkinson, J. and T. Bates, "Guidelines for creation,
selection, and registration of an Autonomous System (AS)",
RFC1930, 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", RFC2374, July
1998.

[RFC2730] Hanna, S., Patel, B. and M. Shah, "Multicast Address
Dynamic Client Allocation Protocol (MADCAP)", RFC2730,
December 1999.

[RFC2770] Meyer, D. and P. Lothberg, "GLOP Addressing in 233/8", RFC
2770, February 2000.

[RFC2909] Radoslavov, P., Estrin, D., Govindan, R., Handley, M.,
Kumar, S. and D. Thaler, "The Multicast Address-Set Claim
(MASC) Protocol", RFC2909, September 2000.

[RFC2974] Handley, M., Perkins, C. and E. Whelan, "Session
Announcement Protocol", RFC2974, October 2000.

[RFC3138] Meyer, D., "Extended Assignments in 233/8", RFC3138, June
2001.

10. Authors' Addresses

David Meyer
Sprint
VARESA0104
12502 Sunrise Valley Drive
Reston VA, 20196

EMail: dmm@sprint.net

Peter Lothberg
Sprint
VARESA0104
12502 Sunrise Valley Drive
Reston VA, 20196

EMail: roll@sprint.net

11. 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 RFCEditor function is currently provided by the
Internet Society.

延伸阅读

文章来源于领测软件测试网 https://www.ltesting.net/


关于领测软件测试网 | 领测软件测试网合作伙伴 | 广告服务 | 投稿指南 | 联系我们 | 网站地图 | 友情链接
版权所有(C) 2003-2010 TestAge(领测软件测试网)|领测国际科技(北京)有限公司|软件测试工程师培训网 All Rights Reserved
北京市海淀区中关村南大街9号北京理工科技大厦1402室 京ICP备10010545号-5
技术支持和业务联系:info@testage.com.cn 电话:010-51297073

软件测试 | 领测国际ISTQBISTQB官网TMMiTMMi认证国际软件测试工程师认证领测软件测试网