DDoS attack

A DDoS (Distributed Denial of Service) attack tries to exhaust network capacity, protocol resources or application functions with traffic from multiple sources. Not every attack produces enormous volume; some exploit expensive operations or limited state. A local firewall may saturate before filtering, so mitigation often requires coordination with a carrier, delivery network or specialist service. Preparation identifies critical services, dependencies, thresholds, contacts and escalation routes. Rate limiting, caching, distribution and filtering can reduce impact but must be tested without blocking legitimate users. Network, application and business measures help distinguish attack, failure and genuine demand. Restoring availability does not prove the cause has disappeared or that no parallel intrusion occurred, so investigation and monitoring should continue.