What is a denial-of-service (DoS) attack?

In a denial-of-service attack, a malevolent actor attempts to prevent a computer or another device from being used by its concerned users by interfering with its regular operation. DoS attacks usually work by overloading a targeted machine with requests until regular traffic cannot be handled, which causes additional users to experience a denial-of-service. A DoS attack is distinguished by the fact that it is initiated by a single computer.  

A few types of DoS attacks include volume-based attacks, protocol attacks, application layer attacks, DDoS attacks (Distributed DoS). A denial-of-service attack's main goal is to overload a device's capacity to the point that it can't handle any more requests.  

Certain indicators may suggest that an attack is in progress, even if it might be challenging to distinguish a DoS attack from other network connectivity issues or excessive bandwidth usage The indicators include:

  1. Unusually poor network speed, as evidenced by lengthy file or website load times
  2. A certain website fails to load
  3. Abrupt disconnections from devices connected to the same network