In computer networking the term Blast Radius is used to define the reach that a faulty configuration change or problem might cause. For example, if a change is made incorrectly to a firewall or router that prevents it passing traffic, the reach of the disruption caused and the impact on other network systems is known as the Blast Radius.

The term is also used when designing application delivery networks to define where Load Balancers should be placed and associated with each application to segment the network and reduce the impact of an issue that might compromise an application — in other words, designing to minimize the Blast Radius. This is especially important when using Software Defined Networking (SDN) as the potential for propagation of an incorrect configuration is increased.