A method, device, and computer-readable medium are disclosed for automatically activating a probe configured to generate test network traffic in response to evaluating a policy that accounts for aggregated information that describes traffic that was processed by a network device. The method includes storing a policy, and evaluating the policy based at least in part on an item of received aggregated information that describes a set of packets that were processed by the network device and sent or received on a network. The probe is activated at least partially in response to evaluating the policy. The probe generates test packets to emulate one or more applications, services, or devices communicating on the network.