Usage Scenario
When the network topology changes, the device receives a topology change event. By default, the device does not send MLD general Query messages in this case. The network topology change triggers ring network protocol recalculation, but multicast data messages cannot be switched to the new path immediately. To enable multicast data flows to be switched to the new forwarding path immediately after the network topology changes, run the mld-snooping send-query enable command to enable the device to send MLD general Query messages to non-router interfaces upon topology changes to learn updated router interface information. This function therefore ensures non-stop forwarding of multicast data flows. Updated interface information includes:
- Router interfaces: In the MSTP protocol networking, MLD general Query messages are sent to all non-router interfaces.
- Member interfaces: After receiving MLD general Query messages, hosts that still require multicast services reply with MLD Report messages. The device then updates information about multicast member interfaces.
Prerequisites
MLD snooping has been enabled globally. Ring network protocols have been enabled on the device.
Follow-up Procedure
The mld-snooping send-query enable command is mainly used for ring networks. When a ring network topology changes, the device sends an MLD Query message with the source IP address FE80::. To change the source IP address, run the mld-snooping send-query source-address command.