Digisol DG-GS4826S Management Manual page 438

C 16 | Multicast Filtering
HAPTER
Layer 2 IGMP (Snooping and Query)
If proxy reporting is disabled, report suppression can still be configured
by a separate attribute as described above.
Interface Version – Sets the protocol version for compatibility with
u
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 proxy general
u
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 427), or as a proxy host when IGMP snooping proxy reporting is
enabled (page 427).
Query Response Interval – The maximum time the system waits for
u
a response to proxy general queries. (Range: 10-31744 tenths of a
second; Default: 10 seconds)
This attribute applies when the switch is serving as the querier
(page 427), or as a proxy host when IGMP snooping proxy reporting is
enabled (page 427).
Last Member Query Interval – The interval to wait for a response to
u
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.
This attribute will take effect only if IGMP snooping proxy reporting is
enabled (see page 427).
Last Member Query Count – The number of IGMP proxy group-
u
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 snooping proxy reporting or
IGMP querier is enabled.
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