IANA Guidelines for IPv4 Multicast Address Assignments
RFC 5771

Internet Engineering Task Force (IETF)                         M. Cotton
Request for Comments: 5771                                     L. Vegoda
BCP: 51                                                            ICANN
Updates: 2780                                                   D. Meyer
Obsoletes: 3138, 3171                                         March 2010
Category: Best Current Practice
ISSN: 2070-1721

         IANA Guidelines for IPv4 Multicast Address Assignments

Abstract

   This document provides guidance for the Internet Assigned Numbers
   Authority (IANA) in assigning IPv4 multicast addresses.  It obsoletes
   RFC 3171 and RFC 3138 and updates RFC 2780.

Status of This Memo

   This memo documents an Internet Best Current Practice.

   This document is a product of the Internet Engineering Task Force
   (IETF).  It represents the consensus of the IETF community.  It has
   received public review and has been approved for publication by the
   Internet Engineering Steering Group (IESG).  Further information on
   BCPs is available in Section 2 of RFC 5741.

   Information about the current status of this document, any errata,
   and how to provide feedback on it may be obtained at
   http://www.rfc-editor.org/info/rfc5771.

Copyright Notice

   Copyright (c) 2010 IETF Trust and the persons identified as the
   document authors.  All rights reserved.

   This document is subject to BCP 78 and the IETF Trust's Legal
   Provisions Relating to IETF Documents
   (http://trustee.ietf.org/license-info) in effect on the date of
   publication of this document.  Please review these documents
   carefully, as they describe your rights and restrictions with respect
   to this document.  Code Components extracted from this document must
   include Simplified BSD License text as described in Section 4.e of
   the Trust Legal Provisions and are provided without warranty as
   described in the Simplified BSD License.

Cotton, et al.            Best Current Practice                 [Page 1]
RFC 5771                IPv4 Multicast Guidelines             March 2010

Table of Contents

   1. Introduction ....................................................2
   2. Terminology .....................................................3
   3. Definition of Current Assignment Practice .......................3
   4. Local Network Control Block (224.0.0/24) ........................4
      4.1. Assignment Guidelines ......................................4
   5. Internetwork Control Block (224.0.1/24) .........................5
      5.1. Assignment Guidelines ......................................5
   6. AD-HOC Blocks (I, II, and III) ..................................5
      6.1. Assignment Guidelines ......................................5
   7. SDP/SAP Block (224.2/16) ........................................5
      7.1. Assignment Guidelines ......................................5
   8. Source-Specific Multicast Block (232/8) .........................6
      8.1. Assignment Guidelines ......................................6
   9. GLOP Block (233/8) ..............................................6
      9.1. Assignment Guidelines ......................................6
      9.2. AD-HOC Block III ...........................................6
   10. Administratively Scoped Block (239/8) ..........................7
      10.1. Assignment Guidelines .....................................7
           10.1.1. Relative Offsets ...................................7
   11. Application Form ...............................................7
      11.1. Size of Assignments of IPv4 Multicast Addresses ...........7
   12. Annual Review ..................................................8
      12.1. Address Reclamation .......................................8
      12.2. Positive Renewal ..........................................8
   13. Use of IANA Reserved Addresses .................................8
   14. IANA Considerations ............................................8
   15. Security Considerations ........................................9
   16. Acknowledgments ................................................9
   17. References .....................................................9
      17.1. Normative References ......................................9
      17.2. Informative References ....................................9

1.  Introduction

   The Internet Assigned Numbers Authority (IANA) (www.iana.org) is
   charged with allocating parameter values for fields in protocols that
   have been designed, created, or are maintained by the Internet
   Engineering Task Force (IETF).  RFC 2780 [RFC2780] provides the IANA
   guidance in the assignment of parameters for fields in newly
   developed protocols.  This memo expands on section 4.4.2 of RFC 2780
   and attempts to codify existing IANA practice used in the assignment