GNS3 vs iperf3
GNS3
gns3.comiperf3
software.es.netSide by side
| Figure | GNS3 | iperf3 |
|---|---|---|
| Price from | Free | Free |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Web | Yes | — |
| Windows | Yes | — |
| macOS | Yes | Yes |
| Linux | Yes | Yes |
| API | — | Yes |
| Self-hosted | Yes | Yes |
| Plans published | 1 | 1 |
| Spec score · Network Testing Software | 8.1 (#9) | 8.1 (#10) |
| Integrations | GNS3 supports Docker instances, QEMU-based appliances, hypervisors including VMware, VirtualBox and Hyper-V, and connections to real networks. | iperf3 was developed initially as the bandwidth tester for the perfSONAR measurement suite, which the project identifies as its primary user base. |
| Purpose | GNS3 lets network engineers emulate, configure, test, and troubleshoot virtual and real networks. | iperf3 measures achievable bandwidth on IP networks and reports throughput, loss, and other test results. |
| Security | GNS3 documentation says a GNS3 server has no authentication enabled by default and should be restricted at the network level. | The project directs reports of potential security issues to [email protected]. |
| Support | GNS3 points users to its documentation and community for help, questions, and bug reports. | The project provides a developer mailing list and GitHub issue tracker for questions and bug reports. |
Plans
In their own words
GNS3
GNS3 is free, open-source software for emulating, configuring, testing, and troubleshooting virtual and real networks. Its graphical client works with a virtual machine, and servers can run locally or remotely. Users can combine emulated devices running actual images with simulated devices, including a built-in layer 2 switch. It supports appliances from vendors such as Cisco, Brocade, Cumulus Linux, and HPE, as well as Docker, QEMU-based appliances, VMware, VirtualBox, Hyper-V, and connections to real networks. The GNS3 Marketplace offers preconfigured appliance templates with recommended settings. It runs on Windows, macOS, and Linux; documentation recommends the GNS3 VM for most Windows and macOS setups and complex topologies. Users must supply their own Cisco IOS images. There are no monthly or yearly license fees, and device capacity depends in practice on the host computer’s CPU and memory. GNS3 is used for networking education, certification practice, proofs of concept, demonstrations, and interoperability testing. A server has no authentication enabled by default and should be restricted at the network level.
iperf3
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.