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Configuring MLD report suppression
When a Layer 2 device receives an MLD report from an IPv6 multicast group member, the Layer 2
device forwards the message to the Layer 3 device directly connected with it. Thus, when multiple
members belonging to an IPv6 multicast group exist on the Layer 2 device, the Layer 3 device
directly connected with it will receive duplicate MLD reports from these members.
With the MLD report suppression function enabled, within a query interval, the Layer 2 device
forwards only the first MLD report of an IPv6 group to the Layer 3 device and will not forward the
subsequent MLD 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 MLD report suppression:
To do...
Use the command...
Remarks
Enter system view
system-view
—
Enter MLD snooping view
mld-snooping
—
Enable MLD report suppression
report-aggregation
Optional
Enabled by default
CAUTION:
On an MLD snooping proxy, MLD 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
The maximum number of IPv6 multicast groups that a port can join can limit the number of multicast
programs available to VOD users, to control the traffic on the port.
Follow these steps configure the maximum number of IPv6 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 IPv6 multicast groups that a
port can join
mld-snooping group-limit
limit
[
vlan
vlan-list
]
Optional
200 by default
NOTE:
•
When the number of IPv6 multicast groups that can be joined on a port reaches the maximum
number configured, the system deletes all the forwarding entries persistent to that port from the
MLD snooping forwarding table, and the hosts on this port need to join IPv6 multicast groups
again.
•
If you have configured static or simulated joining on a port, however, when the number of IPv6
multicast groups on the port exceeds the configured threshold, the system deletes all the
forwarding entries persistent to that port from the MLD snooping forwarding table and applies the
static or simulated joining again, until the number of IPv6 multicast groups joined by the port
comes back within the configured threshold.