ECS4110-28T_Management Guide

C HAPTER 15 | Multicast Filtering
Layer 2 IGMP (Snooping and Query for IPv4)
– 581 –
◆ Proxy Reporting – Enables IGMP Snooping with Proxy Reporting.
(Default: Based on global setting)
When proxy reporting is enabled with this command, the switch
performs “IGMP Snooping with Proxy Reporting” (as defined in DSL
Forum TR-101, April 2006), including last leave, and query
suppression.
Last leave sends out a proxy query when the last member leaves a
multicast group, and query suppression means that specific queries are
not forwarded from an upstream multicast router to hosts downstream
from this device.
Rules Used for Proxy Reporting
When IGMP Proxy Reporting is disabled, the switch will use a null IP
address for the source of IGMP query and report messages unless a
proxy query address has been set.
When IGMP Proxy Reporting is enabled, the source address is based on
the following criteria:
■
If a proxy query address is configured, the switch will use that
address as the source IP address in general and group-specific
query messages sent to downstream hosts, and in report and leave
messages sent upstream from the multicast router port.
■
If a proxy query address is not configured, the switch will use the
VLAN’s IP address as the IP source address in general and group-
specific query messages sent downstream, and use the source
address of the last IGMP message received from a downstream host
in report and leave messages sent upstream from the multicast
router port.
◆ Interface Version – Sets the protocol version for compatibility with
other devices on the network. This is the IGMP Version the switch uses
to send snooping reports. (Range: 1-3; Default: 2)
This attribute configures the IGMP report/query version used by IGMP
snooping. Versions 1 - 3 are all supported, and versions 2 and 3 are
backward compatible, so the switch can operate with other devices,
regardless of the snooping version employed.
◆ Query Interval – The interval between sending IGMP general queries.
(Range: 2-31744 seconds; Default: 125 seconds)
An IGMP general query message is sent by the switch at the interval
specified by this attribute. When this message is received by
downstream hosts, all receivers build an IGMP report for the multicast
groups they have joined.
This command applies when the switch is serving as the querier
(page 570), or as a proxy host when IGMP snooping proxy reporting is
enabled (page 570).