Configuring MLD On-Demand
Context
In a standard Multicast Listener Discovery (MLD) working process, a querier periodically sends Query messages and receives Multicast Listener Report and Done messages from the receiver hosts to learn information about multicast members. If group members on a network seldom change, you can configure MLD on-demand on the querier. After MLD on-demand is configured on the querier, the querier does not send Query messages, reducing MLD packets exchanged between the querier and receiver hosts. The querier maintains multicast membership according to requirements of receiver hosts without actively sending Query messages.
After MLD on-demand is configured, the router:
- Does not send MLD Query messages through the interface.
- Generate MLD group entries that will never age out after receiving Multicast Listener Report messages.
- Delete MLD group entries immediately when receiving Multicast Listener Done messages.
Procedure
- Run system-view
The system view is displayed.
- Run interface interface-type interface-number
The interface view is displayed.
- Run mld on-demand
MLD on-demand is enabled on the interface. The interface then does not send MLD Query messages and MLD group entries on the interface are never aged.
By default, a querier does not maintain group memberships according to requirements of group members, and dynamic entries are aged out when the aging time expires.
If dynamic MLD entries have been generated on the querier, run the reset mld group command to clear these dynamic MLD entries before running the mld on-demand command.
