A method of protecting a networked industrial controller from network storms is disclosed in the specification. The networked industrial controller has a real-time operating system and communication components performing communication exchanges with connected networks. The method comprises steps of:(a) Initializing a watchdog thread monitor thread to have a high priority within the real-time operating system's kernel level;(b) configuring a watchdog thread to periodically (every T.sub.Alive time) send an alive event signal to the watchdog thread monitor thread if all other threads of application programs are operating normally;(c) starting the watchdog thread monitor thread waiting for receiving the alive event signal within a timeout period T.sub.AliveTout (T.sub.AliveTout is longer than T.sub.Alive);(d) identifying a network storm in response to the alive event signal; and(e) controlling the communication exchanges in response to the alive event signal and current phase of the watchdog thread monitor thread.