Configuring mld snooping querier, Enabling mld snooping querier – H3C Technologies H3C WX3000E Series Wireless Switches User Manual

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After receiving an MLD general query or IPv6 PIM hello message from a connected host, the port

becomes a dynamic router port. Before its timer expires, this dynamic router port receives all
multicast packets within the VLAN that the port belongs to, and forwards them to the host, affecting

normal multicast reception of the host.

In addition, the MLD general query and IPv6 PIM hello message that the host sends affects the
multicast routing protocol state on Layer 3 devices, such as the MLD querier or DR election, and

might further cause network interruption.

To solve these problems, you can disable the port from becoming a dynamic router port after receiving

an MLD general query or IPv6 PIM hello message to enhance network security and the control over

multicast users.
To disable a port from becoming a dynamic router port:

Step Command

Remarks

1.

Enter system view.

system-view

N/A

2.

Enter Layer 2 Ethernet
interface view, Layer 2

aggregate interface view,

or port group view.

Enter Layer 2 Ethernet interface view or
Layer 2 aggregate interface view:

interface interface-type

interface-number

Enter port group view:

port-group manual port-group-name

Use either approach.

3.

Disable the port from

becoming a dynamic router
port.

mld-snooping router-port-deny [ vlan
vlan-list ]

By default, a port can
become a dynamic router

port.

NOTE:

This configuration does not affect the static router port configuration.

Configuring MLD snooping querier

Before you configure MLD snooping querier, complete the following tasks:

Enable MLD snooping in the VLAN

Determine the MLD general query interval

Determine the MLD last-member query interval

Determine the maximum response time for MLD general queries

Determine the source IPv6 address of MLD general queries

Determine the source IPv6 address of MLD multicast-address-specific queries

Enabling MLD snooping querier

In an IPv6 multicast network that runs MLD, a Layer 3 multicast device sends periodic MLD queries, so

that all Layer 3 multicast devices can establish and maintain multicast forwarding entries, thus to forward

multicast traffic correctly at the network layer. This Layer 3 multicast device is called MLD querier.
However, a Layer 2 device does not support MLD. Therefore, it cannot send MLD queries by default.
When you enable MLD snooping querier on a Layer 2 device in a VLAN where multicast traffic is

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