H3C Technologies H3C S7500E Series Switches - Manual (Page 46)

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z When the simulated joining function is disabled on a port, the switch sends an IGMP leave
message through that port.
Follow these steps to configure simulated joining:
To do... Use the command... Remarks
Enter system view system-view —
interface interface-type
interface-number
Enter Ethernet port/ONU
port/Layer 2 aggregate interface
view or port group view
port-group manual port-group-name
Required
Use either approach
Configure simulated (*, G) or (S,
G) joining
igmp-snooping host-join
group-address [ source-ip
source-address ] vlan vlan-id
Required
Disabled by default
z Each simulated host is equivalent to an independent host. For example, when receiving an
IGMP query, the simulated host corresponding to each configuration responds
respectively.
z Unlike a static member port, a port configured as a simulated member host will age out like
a dynamic member port.
Configuring Fast Leave Processing
The fast leave processing feature allows the switch to process IGMP leave messages in a fast
way. With the fast leave processing feature enabled, when receiving an IGMP leave message
on a port, the switch immediately removes that port from the outgoing port list of the forwarding
table entry for the indicated group. Then, when receiving IGMP group-specific queries for that
multicast group, the switch will not forward them to that port.
In VLANs where only one host is attached to each port, fast leave processing helps improve
bandwidth and resource usage. However, if fast leave processing is enabled on a port to which
more than one host is attached, when one host leaves a multicast group, the other hosts
attached to the port and interested in the same multicast group will fail to receive multicast data
for that group. Therefore, if the function of dropping unknown multicast traffic is already
enabled on the switch or in the VLANs, the fast leave processing function should not be
enabled.
Configuring fast leave processing globally
Follow these steps to configure fast leave processing globally:
To do... Use the command... Remarks
Enter system view system-view —