On-switch methods for enforcing a policy relating to one or more network switch resources, for detecting and mitigating a network anomaly, and for selectively filtering packets to an externally-accessible port, are provided. The methods may each be embodied as one or more rules held by one or more processor readable media, with one or more of the rules defining one or more conditions to be met by one or more usage-derived packet statistics, and one or more actions to be performed if the one or more conditions are met.