Configuring the router to Deny MLD Messages Without the Router-Alert Option

If user hosts do not want to receive MLD messages without the Router-Alert option, configure the router directly connected to the user hosts to deny all MLD messages without the Router-Alert option.

Context

By default, the router does not check the Router-Alert option in received MLD messages, so it accepts and processes all received MLD messages.

You can perform configurations either globally or on an interface.

The require-router-alert command configuration in the system view takes effect on all interfaces.
The require-router-alert command configuration in the view of an interface takes effect only on the interface. The interface-specific configuration takes precedence over the global configuration. If an interface-specific configuration is not available, the interface uses the global configuration.

Procedure

Global configuration:
1. Run system-view
  The system view is displayed.
2. Run mld
  The MLD view is displayed.
3. Run require-router-alert
  The router is configured to accept and process only MLD messages with the Router-Alert option and discard those without the Router-Alert option.
4. Run commit
  The configuration is committed.
Interface-specific configuration:
1. Run system-view
  The system view is displayed.
2. Run interface interface-type interface-number
  The view of the interface connected to a user host or switch is displayed.
3. Run mld require-router-alert
  The interface is configured to accept and process only MLD messages with the Router-Alert option and discard those without the Router-Alert option.
4. Run commit
  The configuration is committed.