Configuring Layer 2 Multicast MLD Snooping Configuration
User Guide    233
Fast Leave Enable or disable Fast Leave for the VLAN. 
Without Fast Leave, after a receiver sends an MLD done message (equivalent to 
an IGMP leave message) to leave a multicast group, the switch will forward the 
done message to the Layer 3 device (the querier). 
From the point of view of the querier, the port connecting to the switch is a 
member port of the corresponding multicast group. After receiving the done 
message from the switch, the querier will send out a configured number (Last 
Listener Query Count) of Multicast-Address-Specific Queries (MASQs) on that 
port with a configured interval (Last Listener Query Interval), and wait for MLD 
reports. If there are other receivers connecting to the switch, they will response 
to the MASQs before the Last Listener Query Interval expires. If no reports are 
received after the response time of the last query expires, the querier will remove 
the port from the forwarding list of the corresponding multicast group.
That is, if there are other receivers connecting to the switch, the one sent done 
message have to wait until the port ages out from the switch’s forwarding list of 
the corresponding multicast group (the maximum waiting time is decided by the 
Member Port Aging Time).
With Fast Leave enabled on a VLAN, the switch will remove the (Multicast Group, 
Port, VLAN) entry from the multicast forwarding table before forwarding the done 
message to the querier. This helps to reduce bandwidth waste since the switch 
no longer sends the corresponding multicast streams to the VLAN of the port as 
soon as the port receives a done message from the VLAN. 
Report 
Suppression
Enable or disable Report Suppression for the VLAN.
When enabled, the switch will only forward the first MLD report message for 
each multicast group to the MLD querier and suppress subsequent MLD report 
messages for the same multicast group during one query interval. This feature 
prevents duplicate report messages from being sent to the MLD querier.
Member Port 
Aging Time
Specify the aging time of the member ports in the VLAN.
Once the switch receives an MLD report message from a port, the switch adds 
this port to the member port list of the corresponding multicast group. Member 
ports that are learned in this way are called dynamic member ports.
If the switch does not receive any MLD report messages for a specific multicast 
group from a dynamic member port, it will no longer consider this port as a 
member port of this multicast group and delete it from the multicast forwarding 
table.
Router Port 
Aging Time
Specify the aging time of the router ports in the VLAN. 
Once the switch receives an MLD general query message from a port, the switch 
adds this port to the router port list. Router ports that are learned in this way are 
called dynamic router ports.
If the switch does not receive any MLD general query messages from a dynamic 
router port within the router port aging time, the switch will no longer consider this 
port as a router port and delete it from the router port list.
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