This is a countdown showing how much time remains before the device expects the next general query from an external router, and it becomes irrelevant if this device's own query engine is itself active, in which case this device is the one generating queries, not waiting for one. An admin checking multicast health on a service where an external router is expected to be the querier can use this timer to confirm queries are arriving on schedule; a value that reaches zero and stays there without resetting would suggest the expected external querier has gone silent. A value of 45 seconds counting down normally confirms the device is actively expecting, and presumably receiving, periodic queries from an external router.