Cisco pyATS vs iperf3

Cisco pyATS is a Python framework for network testing, automation, and validation, available free under the Apache 2.0 license. It supports sanity, feature, solution, system, and scale test and verification workflows, with reusable data-driven tests ranging from simple checks to complex asynchronous suites. Genie libraries provide device connectivity, parsers, APIs, platform-agnostic feature models, reusable test cases, and a YAML-driven test runner. Built-in device libraries cover Cisco IOS, IOS XE, IOS XR, NX-OS, and ASA; plugins and extensions can add other platforms. Connections can use CLI, NETCONF, or RESTCONF. XPRESSO manages test suites, environments, testbeds, resources, live test views, and archived results with comparisons and analytics. It supports on-demand, bundled, and scheduled runs through Jenkins and Docker backends. Cisco also documents Ansible community integrations and out-of-the-box RobotFramework support. pyATS runs on Linux and macOS and supports self-hosted deployment. Cisco says more than 75% of its codebase is open source on GitHub. Email support is best-effort and usually receives a reply within a day.

iperf3 is a free command-line network measurement tool that reports achievable IP-network bandwidth, throughput, loss, and related results. It includes client and server functions for TCP, UDP, and SCTP tests, with adjustable timing, protocol, and buffer settings. Client or server output can be emitted as JSON, including line-delimited JSON for real-time parsing, and a library version can be embedded in other programs. The project uses a three-clause BSD license and lists Ubuntu Linux, FreeBSD, and macOS as its officially supported platforms. Windows is not officially supported; its FAQ points users with Windows problems toward iperf2. ESnet supplies source distributions rather than binary packages and recommends checking SHA256 checksums. iperf3 began as a perfSONAR bandwidth tester, its primary user base. It is not backwards compatible with the original iperf. Version 3.22 was released September 29, 2026.