Deep Dive into Junos' Storm Control Features

Juniper Networks' Junos operating system offers a plethora of features designed to enhance network performance and security. One such feature is Storm Control, a mechanism that helps protect your network from broadcast, multicast, or unicast storm traffic that could potentially degrade network performance. This blog post will delve into the details of Storm Control, its configuration, and its importance in network management, particularly for those studying for the JNCIS-ENT certification.

What is Storm Control?

Storm Control is a feature that monitors the levels of broadcast, multicast, and unknown unicast traffic entering a switch. When the traffic level exceeds a specified threshold, Storm Control blocks or discards the excessive traffic, thereby preventing it from spreading across the network.

Why is Storm Control Important?

Broadcast, multicast, and unknown unicast traffic can consume significant network resources. In extreme cases, they can lead to a 'traffic storm' that can degrade network performance or even cause network failure. By monitoring and controlling this traffic, Storm Control helps maintain network performance and prevent network outages.

Configuring Storm Control on Junos

Configuring Storm Control on a Junos device involves setting a traffic level threshold and specifying an action to be taken when the threshold is exceeded. Here's an example of how to configure Storm Control on a Junos device:

user@switch# set interfaces ge-0/0/0 unit 0 family ethernet-switching storm-control bandwidth-level 500
user@switch# set interfaces ge-0/0/0 unit 0 family ethernet-switching storm-control action shutdown

In this example, the bandwidth-level is set to 500 kilobits per second. This means that if the traffic level exceeds 500 kbps, the action specified will be triggered. In this case, the action is shutdown, which means the interface will be shut down.

Monitoring Storm Control

You can monitor the status of Storm Control on an interface using the show interfaces storm-control command. Here's an example:

user@switch> show interfaces ge-0/0/0 storm-control

This command displays the Storm Control configuration and status for the specified interface.


Storm Control is a powerful feature in Junos that can help protect your network from traffic storms that can degrade performance. By understanding how to configure and monitor Storm Control, you can enhance your network management skills and prepare for the JNCIS-ENT certification.

Remember, the key to mastering any technical topic is practice. So, don't just read about Storm Control - try configuring it on a Junos device and monitor its operation. This hands-on experience will not only deepen your understanding but also prepare you for the practical aspects of the JNCIS-ENT certification.

In the next blog post, we will delve into another important Junos feature. Stay tuned!

© Ben Jacobson.RSS