Allied Telesis RAPIER I - Manual (Page 55)

Software Version 2.8.1 55
Software Version 2.8.1
C613-10477-00 REV B
Internet Group Management Protocol
(IGMP) Enhancements
This Software Version includes the following enhancements to IGMP:
■ IGMP Proxy on x900 Series Switches
■ IGMP filtering extended to all IGMP message types
■ Monitoring reception of IGMP general query messages
This section describes the enhancements. The new and modified commands to
implement them are described in
Command Reference Updates .
IGMP Proxy on x900 Series Switches
IGMP proxy was previously released on the following products:
■ AR400 Series routers
■ AR700 Series routers
■ AT-8600 Series switches
■ AT-8700XL Series switches
■ AT-8800 Series switches
■ Rapier Series switches
This software version adds support for IGMP proxy on the following x900
Series switches:
■ AT-8948
■ x900-48FE
■ x900-48FE-N
■ AT-9924T
■ AT-9924SP
■ AT-9924T/4SP
■ x900-24XT
■ x900-24XT-N
In a network with a simple tree topology, you can use IGMP proxy to simplify
the configuration of multicast routing. The router or switch at the root of the
tree must run a multicast routing protocol, but all other routers and switches in
the network can be configured as IGMP proxy agents.
The IGMP proxy agent must be configured with a single upstream interface
and one or more downstream interfaces. An upstream interface is an interface
in the direction towards the root of the tree. A downstream interface is an
interface in the direction away from the root of the tree.
The IGMP proxy agent periodically transmits IGMP general membership
queries to the hosts attached to its downstream interfaces. The proxy agent
uses IGMP report and leave messages received on downstream interfaces to
build and maintain a database of multicast group memberships, and reports
changes to the list of multicast groups in the database on the upstream