LevelOne GEL-5261, User Manual

Page: 451 / 570

Chapter 14
| Multicast Filtering
Layer 2 IGMP (Snooping and Query for IPv4)
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If general query suppression is enabled, then these messages are forwarded
only to downstream ports which have joined a multicast service.
◆
Proxy Reporting – Enables IGMP Snooping with Proxy Reporting.
(Options: Enabled, Disabled, Using Global Status; Default: Using Global Status)
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. (Options: 1-3, Using Global Version; Default: Using Global
Version)
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 attribute applies when the switch is serving as the querier ( page 440 ), or as
a proxy host when IGMP snooping proxy reporting is enabled ( page 440 ).