What is Storm Control?

Storm Control is a network feature used to prevent broadcast, multicast, and unknown unicast storms on a switch. It limits the traffic volume to a predefined threshold, preventing network congestion and potential downtime. Storms can occur when devices flood the network with excessive traffic, disrupting communication between network devices. By enabling Storm Control, a switch can block or rate-limit traffic if the thresholds are exceeded, ensuring a stable network performance. This feature is particularly useful in managing large networks and preventing performance degradation caused by traffic overloads.

Storm Control can also be configured per port, allowing administrators to set specific thresholds that trigger actions. Each port can define a state (such as disable or port shutdown), the packet type (broadcast, multicast, or unknown unicast), and a packet rate threshold in packets per second (pps). When the port detects traffic exceeding the set threshold, it can take the defined action, ensuring more granular protection and control across the switch.

Example Scenario: Storm Control preventing network performance issues.

In a large industrial network, multiple devices like HMIs, PLCs, and remote I/O devices are connected to switches. If one device starts sending excessive broadcast traffic due to a misconfiguration or network fault, without Storm Control, this traffic could flood the network and cause significant performance issues.

Content created by Mike Day