A read-create value, defaulting to 2, tuning IGMP's tolerance for packet loss on this subnet; IGMP remains robust to one fewer than this many lost packets. Increasing this value on a lossy subnet makes the router retransmit queries more times before assuming a group has no members, trading slightly slower leave detection for more reliable membership tracking on unreliable links. An admin managing a wireless or otherwise lossy multicast segment might increase this from the default 2 to 3 or higher to reduce the chance of prematurely dropping a group due to lost packets.