This object sets the traffic rate threshold used by storm control for unknown unicast frames (frames destined to a MAC address the switch hasn't learned) on Fast Ethernet ports. An administrator tunes this rate to balance flooding suppression against legitimate bursty traffic, since unknown unicast frames get flooded to all ports until the switch learns the destination. For example, lowering rlUnknowUnicastStormCtrlFastEthernetRate on a port connected to a device with a very static MAC table reduces flooding load from that port without dropping legitimate learned traffic.