Reference Documentation

Napatech SmartNIC
Reference Information


The ntpcap_capture tool captures data to disc received from a pcap interface. The captured file will be stored in pcap file format. It can also be used to measure throughput by not specifying any -f <file> parameter. This tool can also use an NTAPI stream directly, if the stream id is known. The ntpcap_capture tool looks up the pcap interface and lets the pcap implementation do the NTPL programming. Hereafter the tool uses the NTAPI interface directly for optimum performance.


ntpcap_capture -i <interface> -f <file name> [-s <stream id>] [-n] [-l ] [-h]

Table. Commands



-h --help

Displays help text.

-n --nanosec

Specify that the pcap packet header timestamp resolution should be in nanosecond resolution. Default is microsecond resolution.

-f <file> --file <file>

Specifies the file to capture to. The captured data will be stored in pcap file format. If not specified, then the data will be discarded but throughput measurement will still be done.

-i <interface> --interface <interface>

Specify the pcap interface to capture data from.

-l --list

list all available Rx-capable pcap interfaces.

-s <stream id> --streamid <stream id>

If the Napatech NTAPI streamid is known, then this parameter can be used to specify the capture data source. Note: Cannot be used together with the -i parameter.


  • Capture data on an NT40E3 accelerator using a pcap interface as data source. ntpcap_capture -i napa0 -f /tmp/file.pcap -n

  • Capture data on an NT40E3 adapter using a NTPI streamid. ntpcap_capture s 0 -f /tmp/file.pcap -n