Distributed denial of service, explained
A DDoS attack uses distributed sources to overwhelm a network, service or application and reduce availability.
- The field
- Technical
- Reading time
- 1 minute
- In this entry
- Meaning · relevance · limits
The meaning
A DDoS attack uses distributed sources to overwhelm a network, service or application and reduce availability.
Why it matters
Network flooding and expensive application requests may require different defences. Monitoring should identify the affected layer.
The boundary
A quoted mitigation capacity does not guarantee protection against every traffic pattern.
Match the defence to the attack layer
A flood of packets can exhaust a network link, while repeated expensive application requests can consume database or CPU resources at a much lower traffic rate. Network filtering and application protection address different problems. Read the plan’s capacity and scope, then combine suitable rate limits, caching and monitoring with the proposed protection.
- L3/L4 filtering does not establish an application WAF or protection from every L7 request pattern.
- A stated Gbps capacity is not a guarantee of uninterrupted service against all attacks.