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.