The snooping switch is configured to send MLD general queries on all the nonrouter ports, when spanning tree topology changes occur in a network. If the spanning tree mode is RSTP, MLD general queries are sent on all the non router ports, which are the VLANs member ports present in the switch. If the spanning tree mode is MSTP, MLD general queries are sent on all the nonrouter ports of the VLAN mapped for the MSTP instance. Once you enable this command, the switch generates MLD general query messages when a topology change occurs in the network.