max-response-time (MLD view)

Usage Scenario

If hosts send Multicast Listener Report messages immediately after receiving MLD General Query messages, the querier on the local network segment may receive a large number of Multicast Listener Report messages from the hosts at the same time. This may cause congestion on the network.

To avoid such situations, MLD messages specify the maximum response time for MLD General Query messages. When a host receives an MLD Query message, the host starts a timer for the multicast group that it joins. The timer length is a random value between 0 and the maximum response time. When the timer times out, the host sends a Multicast Listener Report message to the querier.

The maximum response time specifies the deadline for the host to send a Multicast Listener Report message. A proper maximum response time allows hosts to respond to MLD Query messages and prevents hosts from sending Report messages at the same time.

Prerequisites

Layer 3 IPv6 multicast has been enabled using the multicast ipv6 routing-enable command in the system view.

Precautions

• A shorter response time allows a multicast device to obtain multicast group member information more quickly, but consumes more bandwidth and system resources.
• The function of this command is the same as that of the mld max-response-time command used in the interface view. The configuration in the MLD view is globally valid, whereas the configuration in the interface view takes effect only for the specified interface. The configuration in the interface view takes precedence over the configuration in the MLD view. The configuration in the MLD view is used only when no configuration is performed in the interface view.