Ostinato is an open-source, cross-platform network packet crafter/traffic generator and analyzer with a friendly GUI and powerful Python API. Craft and send packets of several streams with different protocols at different rates. It is “Wireshark in Reverse”.

Ostinato aims to provide a traffic generator and tester tool for every network engineer and developer - something not possible today with the existing commercial solutions. With the right tool, network developers and engineers can do their jobs better and improve the quality of networking products.


  • Runs on Windows, Linux, BSD and Mac OS X
  • Use via GUI or Python API
  • Open, edit, replay and save PCAP files
  • Support for the most common standard protocols
    • Ethernet/802.3/LLC SNAP
    • VLAN (with QinQ)
    • ARP, IPv4, IPv6, IP-in-IP a.k.a IP Tunnelling (6over4, 4over6, 4over4, 6over6)
    • Any text based protocol (HTTP, SIP, RTSP, NNTP etc.)
    • More protocols in the works …
  • Set a value for any field of any protocol
  • Vary packet fields across packets at run time e.g. changing IP/MAC addresses
  • User provided Hex Dump - specify some or all bytes in a packet
  • User defined script to substitute for an unimplemented protocol (EXPERIMENTAL)
  • Stack protocols in any arbitrary order
  • Create and configure multiple streams
  • Configure stream rates, bursts, no. of packets
  • One agent can control and configure multiple ports on multiple computers generating traffic
  • Multiple agents can share control over a single port on a single computer
  • Exclusive control of a port to prevent the OS from sending stray packets provides a controlled testing environment (Windows only)
  • Statistics Window shows realtime port receive/transmit statistics and rates
  • Capture packets and view them (needs Wireshark to view the captured packets)
  • Framework to add new protocol builders easily




…thanks for developing ostinato: this was a really missing piece in the open-source networking world - Luca Deri ( [Email]

Before I go any further I need to give another shout out to an excellent open source piece of software I found. Ostinato turns you into a packet ninja. There’s literally no limit to what you can do with it. Without Ostinato I could have never gotten beyond this point - Kristian Kielhofner (“Packets of Death” AstLinux, Star2Star) [Blog]

Napatech supports a number of open-source software applications that can also help customers accelerate their development … Ostinato for Traffic Generation [Press Release]

Ostinato is more stable [than similar tools] and has a more complete roadmap [Blog]

If your [sic] looking for GUI based packet generator then Ostinato is one of the best option [Blog]

First - great program - and I’m so happy to see that it’s actively being developed [Email]

Many thanks for developing this great software and giving good support [Email]


January 2016

  • Winners of the VIRL Giveaway announced - Nolan and Anuj T

December 2015

June 2015

See All News


On Nov 26, 2015 Thanksgiving Day, Cisco released Cisco VIRL 1.0 which included an Ostinato container “to provide data-plane traffic generation capabilities” within VIRL alongwith a Video Tutorial.

To celebrate, we are offering a VIRL license (worth $300 each) for two lucky winners.

a Rafflecopter giveaway Thanks to Cisco VIRL for the licenses and Rafflecopter for the giveaway infrastructure.

Mailing List

For queries/bugs/feedback/suggestions, send an email to the mailing list -

You can also join the mailing list or read the archives


Ostinato is licensed under GNU GPLv3

Contributing to Ostinato

You can contribute to Ostinato in many ways -

  • Testing
  • Reporting bugs
  • Improving the documentation
  • Spreading the word (blog, tweet, tell your friends and colleagues)
  • Build/maintain packages for different platforms/distributions
  • and many more …

For all such contributions or any other ideas you may have, please send an email to

For source code contributions (fixes/features etc.), see the Ostinato wiki for -