Allied Telesis RAPIER I, X900-48FE Group, Downstream interfaces have members, Multicast group

56 Internet Group Management Protocol (IGMP) EnhancementsRelease Note

interface. The following table summarises how the IGMP proxy agent processes each IGMP message type.

When this message...	Is received on this interface...	Then the IGMP proxy agent...
Report	downstream	• adds the membership subscription to the multicast
		group membership database
		• forwards the report message on the upstream interface,
		if the membership subscription is for a new multicast
		group
	upstream	• discards the message without processing
Leave	downstream	• removes the membership subscription from the
		multicast group membership database
		• forwards the leave message on the upstream interface,
		if there are no remaining membership subscriptions for
		the multicast group (no other hosts connected to any of
		the downstream interfaces have members of the
		multicast group)
	upstream	• discards the message without processing
Group-specific query	downstream	• discards the message without processing
	upstream	• transmits a report message on the upstream interface,
		if the multicast group membership database contains at
		least one member of the multicast group attached to a
		downstream interface
General query	downstream	• discards the message without processing
	upstream	• transmits a report message on the upstream interface
		for each multicast group in the multicast group
		membership database with at least one member
		attached to a downstream interface

The IGMP proxy agent uses the information maintained in the multicast group membership database to forward multicast data packets received on the upstream interface to all downstream interfaces that have members of the multicast group.

Multicast packet forwarding is enabled as long as:

■a multicast routing protocol is not enabled

■an interface is configured with IGMP proxy in the upstream direction

■at least one interface is configured with IGMP proxy in the downstream direction

To add an IP interface and configure IGMP proxying, use the command:

add ip interface=interface ipaddress={ipadddhcp} [igmpproxy={offupstreamdownstream}] [other-options...]

To configure IGMP proxy on an existing IP interface, use the command:

set ip interface=interface igmpproxy={offupstreamdownstream}]

IGMP proxy is turned off by default.

IGMP must also be enabled on the router or switch and on the interface for

IGMP proxy to function.

Software Version 2.8.1 C613-10477-00 REV B