Multicast router ports for a VLAN can be configured statically or learned dynamically. When a port receives a query message, that port is added to the multicast router port list.
When configuring multicast router ports for a VLAN, you can specify the amount of time after which dynamically learned router entries will be deleted. You can also configure a switch to function as a querier on a particular VLAN, and you can specify the amount of time a switch will wait to determine if hosts are still interested in a specific multicast group.