Getting started with MLD Snooping

MLD is a standard defined in RFC2710 for MLDv1. MLD specifies how a host can register a router in order to receive specific multicast traffic. Configure the switch to use MLD snooping in subnets that receive MLD queries from either MLD or the MLD snooping querier. MLD snooping constrains multicast traffic at Layer 2 by configuring Layer 2 LAN ports dynamically to forward multicast traffic only to those ports that want to receive it.

Robustness Variable allows tuning for the expected packet loss on a subnet. If a subnet is expected to be lossy, the Robustness Variable may be increased. MLD is robust to (Robustness Variable-1) packet losses. The Robustness Variable must not be 0, and should not be 1. The default value is 2.

Query Interval is the interval between general queries sent by the querier. The default interval is 125 seconds. By varying the [Query Interval], an administrator may tune the number of MLD messages on the subnet; larger values cause MLD queries to be sent less often.

Query Response Interval is the maximum response time inserted into the periodic general queries. The default value is 100 (10 seconds) By varying the query response interval, an administrator can tune the burstiness of MLD messages on the subnet; larger values make the traffic less bursty, as host responses are spread out over a larger interval. The number of seconds represented by the query response interval must be less than the query interval.

Last Member Query Interval is the maximum response time inserted into group-specific queries sent in response to Leave Group messages, and is also the amount of time between group-specific query messages. The default value is 10 (1 second). This value may be tuned to modify the "leave latency" of the network. A reduced value results in reduced time to detect the loss of the last member of a group.

Last Member Query Count is the number of Group-Specific Queries sent before the router assumes there are no local members. Default: the Robustness Variable.

Enable MLD Snooping Feature per VLAN Enable/disable the MLD snooping feature for a specific VLAN. All VLAN IDs created are listed here. This feature is disabled by default for newly created and default VLAN IDs.

Router ports specify ports to which MLD routers were connected.