User manual

C HAPTER 17 | Multicast Filtering
Layer 2 IGMP (Snooping and Query)
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ES-2000 Series
◆ 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: 1-2; Default: 2)
This attribute configures the IGMP report/query version used by IGMP
snooping. Versions 1 - 2 are supported, and version 2 is backward
compatible, so the switch can operate with other devices using either
Version 1 or 2.
◆ Last Member Query Interval – The interval to wait for a response to
a group-specific or group-and-source-specific query message.
(Range: 1-31744 tenths of a second in multiples of 10;
Default: 1 second)
When a multicast host leaves a group, it sends an IGMP leave message.
When the leave message is received by the switch, it checks to see if
this host is the last to leave the group by sending out an IGMP group-
specific or group-and-source-specific query message, and starts a
timer. If no reports are received before the timer expires, the group
record is deleted, and a report is sent to the upstream multicast router.
A reduced value will result in reduced time to detect the loss of the last
member of a group or source, but may generate more burst traffic.
◆ Last Member Query Count – The number of IGMP proxy group-
specific or group-and-source-specific query messages that are sent out
before the system assumes there are no more local members.
(Range: 1-255; Default: 2)
This attribute will take effect only if IGMP querier is enabled.