A network device comprising: a first network interface; a second network interface; a monitoring instance having a corresponding monitoring instance name and corresponding filter criteria; a packet filter configured to select, based on the filter criteria, network packets; a forwarding unit configured to, receive, via the first network interface, a network packet of a packet flow, in response to a determination that the network packet is a selected network packet, determine a packet arrival time of the selected network packet at the first network interface, provide the network packet to the second network interface for transmission toward a destination, in response to a determination that the network packet is a selected network packet, determine a packet departure time for the selected network packet from the second network interface; and a flow data exporter configured to, create a flow data record specifying the monitoring instance name for the monitoring instance having the criteria that caused the network packet to be selected, the packet arrival time and the packet departure time, and provide the flow data record in a field of a network flow measurement protocol message to a traffic flow data collector device physically separate from the network device. a first network interface; a second network interface; a monitoring instance having a corresponding monitoring instance name and corresponding filter criteria; a packet filter configured to select, based on the filter criteria, network packets; a forwarding unit configured to, receive, via the first network interface, a network packet of a packet flow, in response to a determination that the network packet is a selected network packet, determine a packet arrival time of the selected network packet at the first network interface, provide the network packet to the second network interface for transmission toward a destination, in response to a determination that the network packet is a selected network packet, determine a packet departure time for the selected network packet from the second network interface; and receive, via the first network interface, a network packet of a packet flow, in response to a determination that the network packet is a selected network packet, determine a packet arrival time of the selected network packet at the first network interface, provide the network packet to the second network interface for transmission toward a destination, in response to a determination that the network packet is a selected network packet, determine a packet departure time for the selected network packet from the second network interface; and a flow data exporter configured to, create a flow data record specifying the monitoring instance name for the monitoring instance having the criteria that caused the network packet to be selected, the packet arrival time and the packet departure time, and provide the flow data record in a field of a network flow measurement protocol message to a traffic flow data collector device physically separate from the network device. create a flow data record specifying the monitoring instance name for the monitoring instance having the criteria that caused the network packet to be selected, the packet arrival time and the packet departure time, and provide the flow data record in a field of a network flow measurement protocol message to a traffic flow data collector device physically separate from the network device.