how about the ddos in swich series S3300

Huawei S3300 switches do not support ddos. The firewall supports Anti-DDoS.
An attacker launches DDoS attacks by controlling many zombie hosts to send a large number of attack packets to the attack target. As a result, links are congested, and system resources are exhausted on the attacked network. In this case, the attack target fails to provide services for legitimate users. Because various types of packets are used in DDoS attacks, to distinguish normal traffic from attack traffic, you need to enable the collection of traffic statistics on the device. Once the volume of the traffic destined for a specific destination address exceeds the specified threshold, the system automatically starts the defense.