H3C Technologies H3C S3100V2 Series Switches User Manual

Page 38

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are attached to the Layer 2 device, the Layer 3 device directly connected with it will receive duplicate

IGMP reports from these members.
With the IGMP report suppression function enabled, within each query cycle, the Layer 2 device
forwards only the first IGMP report per multicast group to the Layer 3 device and will not forward the

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

interface interface-type
interface-number

Enter Ethernet interface/Layer 2
aggregate interface view or port
group view

port-group manual
port-group-name

Required
Use either approach

Configure the maximum number of
multicast groups that a port can

join

igmp-snooping group-limit limit
[ vlan vlan-list ]

Optional
512 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.

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