Ostinato is a network traffic generator that crafts packets exactly as you specify and sends them at a chosen rate from an ordinary computer, with no dedicated hardware. Its author, Srivats P, first wrote it for his own needs as a network engineer and released it as open source in 2010. After fourteen years under the GPL, the project changed course in April 2024: new releases are now closed source and sold by subscription on ostinato.org, while version 1.3.0 remains the last one whose source code is available on GitHub.
What Ostinato is for
Testing a network means feeding it traffic you control. That is what Ostinato does: you define streams, meaning sequences of packets in which you pick every layer, from the Ethernet header to the payload, through VLAN tags, IPv4 or IPv6, TCP, UDP and many other protocols. For each stream you set the packet count, the rate, the frame size and the way certain fields change from one packet to the next. The software then transmits everything on the selected interface and counts what goes out and what comes back.
Its architecture separates the graphical front end, called the controller, from the program that actually emits packets, called Drone. The two can run on the same machine or on different ones, so a single workstation can drive several agents spread across a lab. According to the official site, version 2 adds protocol emulation for DHCP, OSPFv2, BGP and IGMP, per-stream statistics with loss, latency and jitter measurements, PCAP replay and an RFC 2544 benchmark. A Python API automates everything the mouse can do, though it is limited to the Business tier.
A comparison with Scapy, listed in the same category, helps position the tool. Scapy is a free Python library that forges any packet from the command line: unbeatable for a one-off experiment or a script, but it has no graphical interface and no engine designed to sustain a high rate. Ostinato aims at the opposite: a ready-made tool with readable counters, able to saturate a multi-gigabit link and, with the paid Turbo add-on, to reach rates the vendor quotes at 10 to 400 Gbit/s.
The software fits into the usual lab environments. The official documentation has dedicated installation pages for GNS3, EVE-NG, Cisco CML and Containerlab, plus a virtual machine image and a Docker container for Business subscribers.
Who is it for?
Ostinato suits engineers who validate a switch, a firewall or a link, quality assurance teams that need reproducible load scenarios, and trainers who want to show concretely what a frame or a stream is. The Solo tier, restricted to personal use, fits a learner practising at home, while the Pro and Business tiers cover commercial use.
The business model has to be accepted, however. Since 2024 there is no free edition, and the subscription must stay active to keep using the software, as the pricing page states. The highest rates require the Turbo add-on, sold separately. Anyone who wants a free and open tool to build a few packets should turn to Scapy, and anyone willing to compile the old open-source release can still do so from the 1.3.0 archives, knowing that it no longer evolves.
Download Ostinato safely
Official distribution goes only through ostinato.org, where the Get Ostinato link leads to the pricing page. When this article was written, that page listed three tiers billed annually: Solo at $19 per month for Windows and macOS in personal use, Pro at $79 per month adding Linux and commercial use, and Business at $249 per month with the automation API, protocol emulation, the virtual appliance and the Docker container. An Enterprise tier is quoted on request and a trial can be requested through a form. According to the user guide, Windows gets an executable installer that requires the Npcap library, macOS a DMG image, and Linux an archive of deb and rpm packages for RHEL 9 and 10 and Ubuntu 22.04, 24.04 and 26.04.
Because the software is paid, it attracts pirated copies and fake installers. A website offering a free Ostinato 2.x download is not distributing the vendor’s build. The only legitimate files outside the official site are the source archives of version 1.3.0 and earlier on the pstavirs/ostinato GitHub repository, published under GPL v3.
Frequently asked questions
Is Ostinato still open source?
No. In April 2024 the author announced that new versions would be closed source, after fourteen years of open development. Version 1.3.0, released in October 2023, is the last one whose code is published under GPL v3 on GitHub. Versions 2.0 and 2.1 are commercial.
How much does Ostinato cost?
At the time of writing, the pricing page listed annual subscriptions of $19 per month for the Solo tier, $79 for Pro and $249 for Business. The Turbo add-on for very high rates is sold separately. There is no longer a one-time purchase or a free edition.
How does it differ from Scapy?
Scapy is a free Python library for forging and decoding packets inside a script or an interpreter, with no graphical interface. Ostinato is a complete application with streams configured by mouse, per-stream counters and an engine built for high-rate transmission, but it is a paid product.
