Using Internet Group Management Protocol Version 3 (IGMPv3) and Multicast Listener Discovery Protocol Version 2 (MLDv2) for Source-Specific Multicast
RFC 4604
Document | Type | RFC - Proposed Standard (August 2006; No errata) | |
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Authors | Hugh Holbrook , Storigen Systems , Brian Haberman | ||
Last updated | 2015-10-14 | ||
Stream | Internent Engineering Task Force (IETF) | ||
Formats | plain text html pdf htmlized (tools) htmlized bibtex | ||
Stream | WG state | (None) | |
Document shepherd | No shepherd assigned | ||
IESG | IESG state | RFC 4604 (Proposed Standard) | |
Action Holders |
(None)
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Consensus Boilerplate | Unknown | ||
Telechat date | |||
Responsible AD | Margaret Cullen | ||
Send notices to | (None) |
Network Working Group H. Holbrook Request for Comments: 4604 Arastra, Inc. Updates: 3376, 3810 B. Cain Category: Standards Track Acopia Networks B. Haberman JHU APL August 2006 Using Internet Group Management Protocol Version 3 (IGMPv3) and Multicast Listener Discovery Protocol Version 2 (MLDv2) for Source-Specific Multicast 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 (2006). Abstract The Internet Group Management Protocol Version 3 (IGMPv3) and the Multicast Listener Discovery Protocol Version 2 (MLDv2) are protocols that allow a host to inform its neighboring routers of its desire to receive IPv4 and IPv6 multicast transmissions, respectively. Source-specific multicast (SSM) is a form of multicast in which a receiver is required to specify both the network-layer address of the source and the multicast destination address in order to receive the multicast transmission. This document defines the notion of an "SSM-aware" router and host, and clarifies and (in some cases) modifies the behavior of IGMPv3 and MLDv2 on SSM-aware routers and hosts to accommodate source-specific multicast. This document updates the IGMPv3 and MLDv2 specifications. Holbrook, et al. Standards Track [Page 1] RFC 4604 IGMPv3/MLDv2 for SSM August 2006 1. Introduction The Internet Group Management Protocol (IGMP) [RFC1112, IGMPv2, IGMPv3] allows an IPv4 host to communicate IP multicast group membership information to its neighboring routers. IGMP version 3 (IGMPv3) [IGMPv3] provides the ability for a host to selectively request or filter traffic from individual sources within a multicast group. The Multicast Listener Discovery Protocol (MLD) [RFC2710, MLDv2] offers similar functionality for IPv6 hosts. MLD version 2 (MLDv2) provides the analogous "source filtering" functionality of IGMPv3 for IPv6. Due to the commonality of function, the term "Group Management Protocol", or "GMP", will be used to refer to both IGMP and MLD. The term "Source Filtering GMP", or "SFGMP", will be used to refer jointly to the IGMPv3 and MLDv2 group management protocols. The use of source-specific multicast is facilitated by small changes to the SFGMP protocols on both hosts and routers. [SSM] defines general requirements that must be followed by systems that implement the SSM service model; this document defines the concrete application of those requirements to systems that implement IGMPv3 and MLDv2. In doing so, this document defines modifications to the host and router portions of IGMPv3 and MLDv2 for use with SSM, and presents a number of clarifications to their behavior when used with SSM addresses. This document updates the IGMPv3 and MLDv2 specifications. 1.1. 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 [RFC2119]. In order to emphasize the parts of this document that modify the existing protocol specifications ([RFC2710, MLDv2, IGMPv3]), as opposed to merely clarify them, any protocol modifications are marked with the tag "MODIFICATION". 2. Host Requirements for Source-Specific Multicast This section defines the notion of an "SSM-aware" host and then goes on to describe the API requirements and the SFGMP protocol requirements of an SSM-aware host. It is important to note that SSM can be used by any host that supports source filtering APIs and whose operating system supports the appropriate SFGMP. The SFGMP Holbrook, et al. Standards Track [Page 2] RFC 4604 IGMPv3/MLDv2 for SSM August 2006 modifications described in this section make SSM work better on an SSM-aware host, but they are not strict prerequisites for the use of SSM. The 232/8 IPv4 address range is currently allocated for SSM by IANA [IANA-ALLOCATION]. In IPv6, the FF3x::/32 range (where 'x' is a valid IPv6 multicast scope value) is reserved for SSM semantics [RFC3306], although today SSM allocations are restricted toShow full document text