1. A data collecting instrument comprising: an input coupled with an output network port of a processing device, the input configured to receive a destination address of each data packet transmitted from the output network port of the processing device, wherein the processing device is connected to a plurality of processing devices and wherein the processing device is configured to transmit data packets from output network ports of the processing device to other devices of the plurality of processing devices; one or more address registers configured to store information about a destination address range; a counter register configured to store a counter value; and digital circuitry coupled with the input, the one or more address registers, and the counter register, the digital circuitry configured to (i) determine, based on the information stored in the one or more address registers, that the destination address received at the input is within the destination address range; and (ii) increment the counter value stored in the counter register.