A scrubbing center is upstream DDoS-mitigation infrastructure positioned in the traffic path between the public internet and a protected origin. When an attack is detected, traffic is diverted to the scrubbing center (typically via BGP route changes or DNS), where attack packets are filtered out and only clean traffic is forwarded to the origin. A scrubbing center's capability is measured by the aggregate bandwidth and packet-per-second rate it can absorb.
Why it matters in DDoS testing
A scrubbing center is one of the primary controls a DDoS test exercises at Layer 3. Three properties are worth measuring: absorption capacity (the volume it can take before clean traffic degrades), the detection-to-diversion interval (how long until traffic is actually routed through it), and the latency artifact that scrubbing introduces at the application tier. The transient window during cut-over, while routing changes are still propagating and traffic may reach the origin directly, is a frequent and consequential finding.
For how scrubbing centers fit into a full assessment, see The Complete Guide to DDoS Testing.