Multicast & Anycast Group Membership (magma)

Last Modified: 2006-04-18

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Description of Working Group:

Group management protocols are crucial to the operation of multicast
within the Internet, and there are some benefits in extending group
management protocols to also be able to support anycast. These
protocols allow hosts to inform routers of their membership status
within groups.  This working group will be responsible for developing
the functionalities required for group membership reporting and other
related actions.  This group will also address the initial
authentication and access control issues associated with anycast group
membership; this is likely to be limited to shared secrets and message
authentication codes (MACs) much like current routing protocol
security.  Other aspects of Anycast, including architecture and
routing, are outside the groups scope.

The draft names listed below are the starting point for the work in
the WG.

MAGMA specifications will include:

- Core IGMPv3/MLDv2 specifications.  These specifications will describe
  the protocol used between hosts and routers to share group membership
  information.  IGMPv3 and MLDv2 build on IGMPv2 and MLDv1 by adding
  two types of source-specific filtering; "include" (in which the
  system tells the router exactly which sources it desires) and
  "exclude" (in which the system tells the router that it does *not*
  desire a list of sources).

  - IGMPv3: The IDMR working group has submitted this for Proposed
    MAGMA takes ownership after publication as RFC.

  - MLDv2: draft-vida-mld-v2-00.txt

- Multicast Source Filtering API.  This specification describes the API
  used to interact with IGMPv3 and MLDv2 to indicate source filters.
  - draft-ietf-idmr-msf-api-01.txt

- Host determination of network group membership.  In a multicast
  environment, systems may be interested in learning whether or not
  there are any group members, in order to save the trouble of sending
  data that nobody is listening to.

  - Multicast Source Notification of Interest Protocol:

- Multicast forwarding in tree topologies using IGMP/MLD Proxying
  - Create a single document from:
    - draft-ietf-idmr-igmp-proxy-00

    - draft-he-mixed-igmp-proxy-00

- Source-Specific Multicast (SSM) consideration document.  This work
  will describe the use of IGMPv3/MLDv2 in an SSM environment.
  - draft-holbrook-idmr-igmpv3-ssm-01.txt

- Considerations for "IGMP snooping" switches (switches that watch IGMP
  exchanges in order to determine multicast forwarding behavior)

- Multicast Router Discovery:
  The MAGMA group has taken ownership of this draft over from IDMR.
  It will be revised and submitted as a Proposed Standard.

- Snooping Considerations: draft-ietf-magma-mrdisc-00.txt
  (previous revisions draft-ietf-idmr-snoop-XX.txt)

- Group management MIBs
  - update RFC 2933 for IGMPv3
  - update RFC 3019 for MLDv2

- Interaction between IGMP/MLD and routing protocols
  - draft-ietf-idmr-igmpv3-and-routing-00.txt

- Extensions to MLD supporting anycast group memberships including
  authentication and access control mechanisms
  - draft-haberman-ipngwg-host-anycast-00.txt

In addition, this working group will coordinate with other IETF working
groups where multicast and anycast group management protocols are
utilized as well as coordinating with the Multicast Security WG.

Goals and Milestones:

Done    Submit IGMPv3/MLDv2 Interfactions with Routing Protocols as Informational
Done    Submit IGMP/MLD Proxying Specification as Proposed Standard
Done    Submit IGMP & MLD Snooping Considerations as Informational
Done    Submit SSM considerations for IGMPv3 & MLDv2 as Proposed Standard
Done    Submit Multicast Source Filtering API as Informational
Done    Submit MRD as Proposed Standard
Done    Submit IGMPv3/MLDv2 MIB as Proposed Standard


Multicast Group Membership Discovery MIB (0 bytes)

Request For Comments:

IANA Considerations for IGMP (RFC 3228) (6473 bytes)
Source Address Selection for the Multicast Listener Discovery (MLD) Protocol (RFC 3590) (11554 bytes) updates RFC 2710
Socket Interface Extensions for Multicast Source Filters (RFC 3678) (36320 bytes)
Multicast Listener Discovery Version 2 (MLDv2) for IPv6 (RFC 3810) (153579 bytes) updates RFC 2710/ updated by RFC 4604
Multicast Router Discovery (RFC 4286) (35540 bytes)
Considerations for Internet Group Management Protocol (IGMP) and Multicast Listener Discovery (MLD) Snooping Switches (RFC 4541) (38555 bytes)
Using Internet Group Management Protocol Version 3 (IGMPv3) and Multicast Listener Discovery Protocol Version 2 (MLDv2) for Source-Specific Multicast (RFC 4604) (23370 bytes) updates RFC 3810,RFC 3376
Internet Group Management Protocol (IGMP)/ Multicast Listener Discovery (MLD)-Based Multicast Forwarding ( (RFC 4605) (25558 bytes)
Internet Group Management Protocol Version 3 (IGMPv3) / Multicast Listener Discovery Version 2 (MLDv2) and Multicast Routing Protocol Interaction (RFC 5186) (12403 bytes)