The symmetric scrubbing scheme requires routing of your inbound bandwidth through the DDoS‑Guard network, as well as all outbound bandwidth of the protected prefixes. Outbound bandwidth analysis gives the scrubbing system more input data, thereby allowing you to make the most accurate decisions.
Asymmetric scrubbing scheme doesn't require routing of outbound bandwidth of protected networks.
With both symmetric and asymmetric schemes, only inbound bandwidth is affected. We recommend using the symmetric scheme: it is more effective by providing additional analysis of outbound traffic.
Learn more about DDoS-Guard scrubbing schemes