Broadcast Storm

What Does Broadcast Storm Mean?

A broadcast storm occurs when a network system is overwhelmed by continuous multicast or broadcast traffic. When different nodes are sending/broadcasting data over a network link, and the other network devices are rebroadcasting the data back to the network link in response, this eventually causes the whole network to melt down and lead to the failure of network communication.


There are many reasons a broadcast storm occurs, including poor technology, low port rate switches and improper network configurations.

A broadcast storm is also known as a network storm.

Techopedia Explains Broadcast Storm

Although computer networks and network devices are very intelligent and efficient, networks and network devices sometimes fail to provide 100% efficiency. The broadcast storm is one of the major deficiencies in computer network systems.

For example, suppose there is a small LAN network consisting of three switches (Switch A, Switch B and Switch C), and three network segments (Segment A, Segment B and Segment C). Two nodes are attached within this network. Node A is attached to Segment B, while Node B is directly attached to Switch A. Now, if Node B wants to transmit a data packet to Node A, then traffic is broadcast from Switch A over to Segment C; if this fails, then Switch A also broadcasts traffic over Segment A. Because Node A neither attaches to Segment C, nor Segment A, these switches would further create a flood to Segment B. If neither device/switch has learned the Node A address, then traffic is sent back to Switch A. Hence, all devices/switches keep sending and resending the traffic, eventually resulting in a flood loop or broadcast loop. The final result is that the network melts down, causing failure in all network links, which is referred to as a broadcast storm.

The following elements play an active role in the creation of a broadcast storm:

  • Poor network management
  • Poor monitoring of the network
  • The use of cheap devices, including hubs, switches, routers, cables, connectors, etc.
  • Improperly maintained network configuration and inexperienced network engineers
  • The lack of a network diagram design, which is needed for proper management and to provide guidelines for all network traffic routes. This can be done on paper and with the help of application software that creates an automated network diagram.

Related Terms

Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.