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Sample captures

You need a .pcap to do anything with the suite. Here's where to get one.

Make your own

The most representative capture is one of your own traffic:

$ sudo tcpdump -i eth0 -w mycapture.pcap -c 1000

Capture with a full snap length if you plan to benchmark, so packets aren't truncated:

$ sudo tcpdump -i eth0 -s 0 -w mycapture.pcap

Check what you got:

$ tcpcapinfo mycapture.pcap

Captures shipped with the source

The source tree includes small captures under test/ used by the test suite — handy for quick experiments:

File Notes
test/test.pcap General-purpose mixed capture.
test/test_nano.pcap Nanosecond-timestamp capture.

These are intentionally tiny (test fixtures), so loop them (--loop) if you need sustained traffic.

Well-known public sample sets

The Tcpreplay project has long referenced a couple of sample captures for performance demos:

File Rough size Good for
smallFlows.pcap small Quick functional tests; many flows with --unique-ip.
bigFlows.pcap larger Sustained load and flow-heavy performance tests.

Check the project website for current download links.

Other sources

  • Wireshark sample captures — a large community collection of protocol examples.
  • Your capture tool of choice — anything that writes standard pcap (or pcap-ng, with a recent libpcap) works.

Retarget before replaying

A downloaded capture carries someone else's addresses. Before sending it at a specific device, retarget it with tcprewrite so the MACs and IPs match your lab.