How does an S series switch enabled with Layer 2 multicast send Query messages when the network topology changes

For an S series switch, when the ring network topology changes, Layer 2 multicast responds to two events by sending two Query messages with different source addresses.
- Responds to the link change event of the ring network.
Run the igmp-snooping send-query enable command to enable the switch to send IGMP Query messages in response to link change events. When receiving a link change event, the Layer 2 multicast module sends a Query message with source address to all non-router ports. The source address can be changed using the igmp-snooping send-query source-address command.
- Responds to the event that the interface changes from the Blocked state to the Forwarding state.
Layer 2 multicast sends a Query message whose source address is 0. The message is sent to only the interface of which the status changes.

According to RFCs, Query messages whose source address is 0 cannot be used for querier election. Therefore, the Query message sent when the interface status changes will not affect querier election, but the Query message sent when the link changes may affect querier election. You can configure a static router interface to prevent Query messages from affecting querier election.

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