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subsequent IGMP reports from the same multicast group to the Layer 3 device. This helps reduce
the number of packets being transmitted over the network.
Follow these steps to configure IGMP report suppression:
To do...
Use the command...
Remarks
Enter system view
system-view
—
Enter IGMP snooping view
igmp-snooping
—
Enable IGMP report suppression
report-aggregation
Optional
Enabled by default
CAUTION:
On an IGMP snooping proxy, IGMP membership reports are suppressed if the entries for the
corresponding groups exist in the forwarding table, whether the suppression function is enabled or
not.
Configuring maximum multicast groups that a port can join
To regulate multicast traffic on a port, configure the maximum number of multicast groups that the
port can join.
Follow these steps to configure the maximum number of multicast groups that a port can join:
To do...
Use the command...
Remarks
Enter system view
system-view
—
Enter Ethernet interface/Layer 2
aggregate interface view or port
group view
interface
interface-type
interface-number
Required
Use either approach
port-group
manual
port-group-name
Configure the maximum number
of multicast groups that a port can
join
igmp-snooping group-limit
limit
[
vlan
vlan-list
]
Optional
256 by default
NOTE:
•
When the number of multicast groups that a port has joined reaches the maximum number
configured, the system deletes all the forwarding entries persistent to that port from the IGMP
snooping forwarding table, and the hosts on this port need to join the multicast groups again.
•
If you have configured static or simulated joins on a port, however, when the number of multicast
groups on the port exceeds the configured threshold, the system deletes all the forwarding
entries persistent to that port from the IGMP snooping forwarding table and applies the static or
simulated joins again, until the number of multicast groups joined by the port comes back within
the configured threshold.
Configuring multicast group replacement
For various reasons, the number of multicast groups that can be joined on the current switch or a port
might exceed the upper limit for the switch or the port. In addition, in some specific applications, a
multicast group newly joined on the switch must replace an existing multicast group automatically. A
typical example is channel switching. That is, to join a new multicast group, a user switches from the
current multicast group to the new one.