A DoS—or denial of service—attack is used by an attacker to make a service or resource unavailable to its users by flooding the system with superfluous requests, which causes the system to queue up those requests causing a disruption in the service.

The attack can be mitigated through the use of different techniques, implemented at different levels, such as the following:

• Adding a firewall rule to deny traffic from a given untrusted source
• Using services from the cloud security providers, who can analyze the incoming traffic and block it before it reaches the application infrastructure, helping to mitigate the DoS attack
• Configuring the infrastructure to sink the traffic to a node where there is no application running, or by rerouting the traffic to a nonexistent network interface by using DNS rules