3Com Switch 4800G 24-Port Configuration Manual page 593

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Configuring Dropping
Unknown IPv6 Multicast
Data
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Configuring MLD Report
Suppression
To do...
Enter system view
Enter the Enter Ethernet
corresponding view port view
Enter port group
view
Enable IPv6 multicast source port filtering
When enabled to filter IPv6 multicast data based on the source ports, the device is
automatically enabled to filter IPv4 multicast data based on the source ports.
Unknown IPv6 multicast data refers to IPv6 multicast data for which no forwarding
entries exist in the MLD Snooping forwarding table: When the switch receives
such IPv6 multicast traffic:
With the function of dropping unknown IPv6 multicast data enabled, the
■
switch drops all unknown IPv6 multicast data received.
With the function of dropping unknown IPv6 multicast data disabled, the
■
switch floods unknown IPv6 multicast data in the VLAN to which the unknown
IPv6 multicast data belongs.
Follow these steps to enable dropping unknown IPv6 multicast data in a VLAN:
To do...
Enter system view
Enter VLAN view
Enable dropping unknown
IPv6 multicast data
When enabled to drop unknown IPv6 multicast data, the device is automatically
enabled to drop unknown IPv4 multicast data.
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:
Configuring an MLD Snooping Policy
Use the command...
system-view
interface interface-type
interface-number
port-group { manual
port-group-name |
aggregation agg-id }
mld-snooping
source-deny
Use the command...
system-view
vlan vlan-id
mld-snooping
drop-unknown
593
Remarks
-
Use either command
Required
Disabled by default
Remarks
-
-
Required
Disabled by default