The designated device (typically a managed network switch) responsible for sending periodic queries to the network to ask connected devices which multicast groups they wish to remain subscribed to. In an entertainment lighting context: these queries prompt devices like DMX nodes and gateways to respond with IGMP Membership Reports: confirming they still require their assigned sACN universes. Without an active IGMP Querier: switches with IGMP snooping enabled will eventually time out their forwarding tables and default to flooding all multicast traffic as broadcast. At least one switch on the network must act as the querier: and query intervals (typically set to 30 seconds) must remain consistent across the system. Professional switches designed for live entertainment: such as Luminex GigaCore models: ship with both IGMP snooping and the IGMP Querier enabled by default to ensure out of the box stability.