Allocation Guidelines for IPv6 Multicast Addresses
RFC 3307

• Status
• IESG evaluation record
• IESG writeups
• Email expansions
• History

• Versions
• 04

Network Working Group                                        B. Haberman
Request for Comments: 3307                                    Consultant
Category: Standards Track                                    August 2002

          Allocation Guidelines for IPv6 Multicast Addresses

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Copyright Notice

   Copyright (C) The Internet Society (2002).  All Rights Reserved.

Abstract

   This document specifies guidelines that must be implemented by any
   entity responsible for allocating IPv6 multicast addresses.  This
   includes, but is not limited to, any documents or entities wishing to
   assign permanent IPv6 multicast addresses, allocate dynamic IPv6
   multicast addresses, and define permanent IPv6 multicast group
   identifiers.  The purpose of these guidelines is to reduce the
   probability of IPv6 multicast address collision, not only at the IPv6
   layer, but also at the link-layer of media that encode portions of
   the IP layer address into the MAC layer address.

Haberman                    Standards Track                     [Page 1]
RFC 3307          IPv6 Multicast Addresses Guidelines        August 2002

Table of Contents

   1. Terminology.....................................................2
   2. Introduction....................................................2
   3. Applicability...................................................3
   4. Group ID Selection Guidelines...................................3
   4.1  Permanent IPv6 Multicast Addresses............................4
   4.2  Permanent IPv6 Multicast Group Identifiers....................4
   4.3  Dynamic IPv6 Multicast Addresses..............................4
   4.3.1 Server Allocation............................................5
   4.3.2 Host Allocation..............................................5
   5. IANA Considerations.............................................5
   6. Security Considerations.........................................6
   7. Acknowledgements................................................6
   8. References......................................................6
   Author's Address...................................................7
   Full Copyright Statement...........................................8

1. Terminology

   The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
   "SHOULD", "SHOULD NOT", "RECOMMENDED",  "MAY", and "OPTIONAL" in this
   document are to be interpreted as described in [RFC 2119].

   The term "group ID", throughout this document, conforms to the
   definition contained in [UNIMCAST], that is, the low-order 32 bits of
   the IPv6 multicast address.

2. Introduction

   This document specifies guidelines that MUST be implemented by any
   entity responsible for allocating IPv6 multicast addresses.  This
   includes, but is not limited to, any documents or entities wishing to
   assign permanent IPv6 multicast addresses, allocate dynamic IPv6
   multicast addresses, and define permanent IPv6 multicast group
   identifiers.  The purpose of these guidelines is to reduce the
   probability of IPv6 multicast address collision, not only at the IPv6
   layer, but also at the link-layer of media that encode portions of
   the IP layer address into the link-layer address.

   With the current IPv6 address architecture [ADDRARCH] and the
   extension to the multicast address architecture specified in
   [UNIMCAST], a set of guidelines is needed for entities assigning any
   flavor of IPv6 multicast addresses.

   The current approach of several physical media [RFC 2464][RFC 2467]
   is to map a portion of the IPv6 multicast address into a link-layer
   destination address.  This is accomplished by taking the low order 32

Haberman                    Standards Track                     [Page 2]
RFC 3307          IPv6 Multicast Addresses Guidelines        August 2002

   bits (henceforth called the group ID) of the IPv6 multicast address
   and including them in the link-layer destination address.  Group IDs,
   less than or equal to, 32 bits long will generate unique link-layer
   addresses within a given multicast scope.

   These guidelines specify how the group ID of the IPv6 multicast
   address are chosen and assigned.  The guidelines specify several
   mechanisms that can be used to determine the group ID of the
   multicast address, based on the type of allocation being done.

3. Applicability

   These guidelines are designed to be used in any environment in which
   IPv6 multicast addresses are delegated, assigned, or selected.  These
   guidelines are not limited to use by MADCAP [RFC 2730] servers.  The