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Step Command
Remarks
2.
Enter VLAN view.
vlan
vlan-id
N/A
3.
Enable dropping unknown
multicast data.
igmp-snooping drop-unknown
Disabled by default.
Enabling IGMP report suppression
When a Layer 2 switch receives an IGMP report from a multicast group member, the switch forwards
the message to the directly connected Layer 3 device. When multiple members of a multicast group
are attached to the Layer 2 switch, the Layer 3 device might receive duplicate IGMP reports for the
multicast group.
With the IGMP report suppression function enabled, within each query interval, the Layer 2 switch
forwards only the first IGMP report for a multicast group to the Layer 3 device. It does not forward the
subsequent IGMP reports for the same multicast group. This helps reduce the number of packets
being transmitted over the network.
On an IGMP snooping proxy, IGMP reports for a multicast group are suppressed if a matching
forwarding entry exists, whether the suppression function is enabled or not.
To enable IGMP report suppression:
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter IGMP-snooping view.
igmp-snooping
N/A
3.
Enable IGMP report
suppression.
report-aggregation
Enabled by default.
Setting the maximum number of multicast groups that a port
can join
You can set the maximum number of multicast groups that a port can join to regulate traffic on the
port.
If the number of multicast groups the port has joined exceeds the configured maximum value, the
system deletes the forwarding entries associated with the port. The hosts attached to this port need
join multicast groups again until the number of multicast groups that the port joins reaches the
maximum value.
•
If the port has been configured as a static member port, the system applies the configurations to
the port again.
•
If you have configured simulated joining on the port, the system establishes corresponding
forwarding entry for the port after receiving a report from the simulated member host.
To set the maximum number of multicast groups that a port can join:
Step Command
Remarks
1.
Enter system view.
system-view
N/A
2.
Enter Layer 2 Ethernet
interface view or Layer 2
aggregate interface view, or
enter port group view.
•
Enter Layer 2 Ethernet
interface view or Layer 2
aggregate interface view:
interface
interface-type
interface-number
Use either command.
