Internet Group Management Protocol (IGMP) / Multicast Listener Discovery (MLD)-Based Multicast Forwarding ("IGMP/MLD Proxying")
RFC 4605

Approval announcement
Draft of message to be sent after approval:

From: The IESG <iesg-secretary@ietf.org>
To: IETF-Announce <ietf-announce@ietf.org>
Cc: Internet Architecture Board <iab@iab.org>,
    RFC Editor <rfc-editor@rfc-editor.org>, 
    magma mailing list <magma@ietf.org>, 
    magma chair <magma-chairs@tools.ietf.org>
Subject: Protocol Action: 'IGMP/MLD-based Multicast Forwarding 
         ('IGMP/MLD Proxying')' to Proposed Standard 

The IESG has approved the following document:

- 'IGMP/MLD-based Multicast Forwarding ('IGMP/MLD Proxying') '
   <draft-ietf-magma-igmp-proxy-07.txt> as a Proposed Standard

This document is the product of the Multicast & Anycast Group Membership 
Working Group. 

The IESG contact persons are Margaret Wasserman and Mark Townsley.

A URL of this Internet-Draft is:
http://www.ietf.org/internet-drafts/draft-ietf-magma-igmp-proxy-07.txt

Technical Summary
 
In certain topologies, it is not necessary to run a multicast routing
protocol. It is sufficient for a device to learn and proxy group
membership information and simply forward multicast packets based
upon that information.  This draft describes a mechanism for
forwarding based solely upon Internet Group Management Protocol
(IGMP) or Multicast Listener Discovery (MLD) membership information.
 
Working Group Summary
 
This document is a work item of the MAGMA WG.

There is a discussion in the draft about the inability of the IGMP proxy 
mechanism defined in this draft  to detect "upstream loops", and it is 
expected that administrators will either avoid configuring their networks 
in loops or run a multicast routing protocol.  This issue was discussed 
within the MAGMA WG, and the WG did not choose to  include any 
mechanism (i.e. probes) for loop detection. 

The WG chose to use the Querier Election mechanism described in the 
draft  to ensure that there will only be a single forwarder if there is more
than one proxy device on the same link, but this will not eliminate the
possibility of all types of loops, see section 3.0 of the draft for more
details about this.
 
Protocol Quality
 
This document was reviewed for the IESG by Margaret Wasserman.