Allied Telesis AT-S63 - Manual (Page 238)

Chapter 17: Denial of Service (DoS) Defense Commands
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Telesyn recommends that you activate this defense on only one port
at a time, and only on a port where ingress fragments comprise only
a small percentage of its total traffic.
Example
The following command activates the defense on port 22:
set dos teardrop port=22 state=enable