Black Box LGB6026A, Management Manual

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HAPTER
16 | Multicast Filtering
Layer 2 IGMP (Snooping and Query)
When IGMP snooping is disabled globally, snooping can still be
configured per VLAN interface, but the interface settings will not take
effect until snooping is re-enabled globally.
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Version Exclusive – Discards any received IGMP messages (except for
multicast protocol packets) which use a version different to that
currently configured by the IGMP Version attribute. (Default: Disabled)
If version exclusive is disabled on a VLAN, then this setting is based on
the global setting configured on the Multicast > IGMP Snooping >
General page. If it is enabled on a VLAN, then this setting takes
precedence over the global setting.
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Immediate Leave Status – Immediately deletes a member port of a
multicast service if a leave packet is received at that port and
immediate leave is enabled for the parent VLAN. (Default: Disabled)
If immediate leave is not used, a multicast router (or querier) will send
a group-specific query message when an IGMPv2 group leave message
is received. The router/querier stops forwarding traffic for that group
only if no host replies to the query within the specified time out period.
Note that this time out is defined by Last Member Query Interval *
Robustness Variable (fixed at 2 as defined in RFC 2236).
If immediate leave is enabled, the switch assumes that only one host is
connected to the interface. Therefore, immediate leave should only be
enabled on an interface if it is connected to only one IGMP-enabled
device, either a service host or a neighbor running IGMP snooping.
This attribute is only effective if IGMP snooping is enabled, and IGMPv2
snooping is used.
◆
Multicast Router Discovery – MRD is used to discover which
interfaces are attached to multicast routers. (Default: Enabled)
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General Query Suppression – Suppresses general queries except for
ports attached to downstream multicast hosts. (Default: Disabled)
By default, general query messages are flooded to all ports, except for
the multicast router through which they are received.
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.
(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 neither specific
queries nor general queries are forwarded from an upstream multicast
router to hosts downstream from this device.