A network outage is a loss of connectivity or service that stops systems from communicating normally. It may affect internet access, internal applications, authentication, file sharing, production networks, or the links between sites and cloud services. In practice, an outage can come from hardware failure, misconfiguration, power loss, routing problems, or a cyberattack that disables infrastructure.
In cyber security, network outages matter because availability is a core part of defense and operations. Attackers often aim to cause outages with ransomware, destructive malware, or denial-of-service traffic, while defenders use segmentation, redundancy, and failover planning to limit impact. Even when data is not stolen, an outage can still halt ordering, manufacturing, shipping, or incident response. That is why investigators treat it as both an operational disruption and a possible security signal.