17.1.2 Notes on using storm control

(1) Storm Detection and Recovery Detection

The Switch determines that a storm has occurred when the number of frames received per second exceeds the receive rate set in the configuration. After a storm occurs, if the number of frames received within one second remains at or below the receive rate for 30 seconds, it is judged that the storm has recovered.

If a port is blocked when a storm occurs, recovery from a storm cannot be detected because the port is no longer receiving any frames. If a port is shut down when a storm occurs, use a method other than the Switch, such as a network monitoring device, to confirm that the storm has recovered.

(2) Clear statistics on storm detection

The action to be performed when a storm is detected is performed when the specified receive rate exceeds the number of frames received within one second. If the statistic is cleared by the operation command clear counters when a storm is detected, correct actions might not be performed.