Ostinato is a packet crafter, network traffic generator and analyzer with a friendly GUI. Also a powerful Python API for network test automation. Craft and send packets of several streams with different protocols at different rates. Think of it as “Wireshark in Reverse”.

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

What Ostinato cannot do

  • Ostinato is stateless - stateful connection-oriented TCP connections are not supported. Please try TRex or Warp17 instead.
  • Ostinato cannot be used for generating fake traffic to websites


  • Useful for both network load testing and functional testing
  • Use via GUI or Python API
  • Create and configure multiple streams
  • Configure stream rates, bursts, no. of packets
  • Interface level receive/transmit statistics and rates for realtime network monitoring and measurement
  • Network Device Emulation (ARP and ICMP) for multiple IP hosts to aid in network traffic simulation
  • 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)
    • TCP (stateless), UDP, ICMPv4, ICMPv6, IGMP, MLD
    • Any text based protocol - HTTP, SIP, RTSP, NNTP etc. (underlying transport will be stateless however)
    • 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
  • Stack protocols in any arbitrary order to test error cases
  • User provided Hex Dump - specify some or all bytes in a packet
  • User defined script to substitute for an unimplemented protocol (EXPERIMENTAL)
  • Open and edit PCAP files, replay and save back
  • One controller, many agents
  • Many controllers can share an agent
  • Exclusive control of a port to prevent the OS from sending stray packets provides a controlled testing environment (Windows only)
  • Capture network traffic (needs Wireshark to view the captured packets)
  • Cross-Platform - runs on Windows, Linux, BSD and Mac OS X
  • FLOSS - Free, Libre, Open-Source Software
  • Framework to add new protocol builders easily


Ostinato is open-source software licensed under GNU GPLv3




December 2017

October 2016

  • Winners of the VIRL Giveaway 2016 announced - Shane S and Sooraj T

June 2016

March 2016

See All News


…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]


Want multi-core traffic generation and 10Gbps speed support in Ostinato? Please donate to help acquire hardware to develop these features.

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