What is a DNS flood: Query Flood?

DNS servers provide the roadmap to the Internet, and help clients find the servers they are looking for. A DNS query flood uses a network of clients to target a single server with floods of valid requests.

Because this type of attack involves flooding a single DNS server with valid requests, it is difficult for a DNS server to distinguish between a DNS query flood and normal, heavy traffic.

F5 BIG-IP DNS uses DNS Express functionality to mitigate these attacks through the intelligent application of computational power. By scaling linearly across multiple processing cores, DNS Express protects the perimeter by handling all DNS traffic—valid and invalid—as much as an order of magnitude faster than a traditional DNS server.