Sending IGMP Query Messages upon Topology Changes
Context
Changes of the Layer 2 network topology may trigger changes of the multicast forwarding paths. When a link fails, the switch sends IGMP Query messages and the group members reply with IGMP Report messages. The switch then updates information about multicast member ports based on the IGMP Report messages. In this manner, multicast packets can be switched to new forwarding paths quickly.
Procedure
- Run system-view
The system view is displayed.
- Run igmp snooping send-query enable
IGMP Query messages are sent upon topology changes.
By default, the switch is disabled from sending IGMP Query messages upon topology changes.
This command enables the switch to send IGMP Query messages (the source IP address is 192.168.0.1 by default) upon topology changes, and update information about multicast member ports quickly, so that multicast packets to the downstream members are interrupted only for a short period.
- (Optional) Run igmp snooping send-query source-address ip-address
The source IP address of an IGMP General Query message is configured.
By default, the source IP address of an IGMP General Query message sent upon topology changes is 192.168.0.1. If this IP address is used by another device on the network, use this command to set another IP address.
- Run commit
The configuration is committed.
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