This field sets, in seconds, how long the switch remembers a dynamically learned multicast router port in the IGMP snooping interface table before aging it out if no further router traffic is seen. An administrator adjusts this to control how quickly the switch stops treating a port as a multicast-router uplink after that router goes quiet. For example, increasing rlIgmpSnoopRouterAgingTime prevents flapping router-port detection on a link where the upstream router sends queries only infrequently.