GNS3 vs Invariant
GNS3
gns3.com
Invariant
invariant.techSide by side
| Figure | GNS3 | Invariant |
|---|---|---|
| Price from | Free | Free |
| Free plan | Yes | Yes |
| Free trial | — | — |
| Open source | — | — |
| Web | Yes | Yes |
| Windows | Yes | — |
| macOS | Yes | — |
| Linux | Yes | — |
| API | — | Yes |
| Self-hosted | Yes | — |
| Plans published | 1 | 1 |
| Spec score · Network Testing Software | 8.1 (#9) | 7.8 (#18) |
| Integrations | GNS3 supports Docker instances, QEMU-based appliances, hypervisors including VMware, VirtualBox and Hyper-V, and connections to real networks. | The maker lists Jenkins, GitHub Actions, LibreNMS, Netmiko, Aerleon, Capirca, IPAM, and SIEM workflows as integration options. |
| Purpose | GNS3 lets network engineers emulate, configure, test, and troubleshoot virtual and real networks. | Invariant validates network configurations against user-provided rules in a cross-vendor digital twin to identify connectivity problems and unwanted security gaps. |
| Security | GNS3 documentation says a GNS3 server has no authentication enabled by default and should be restricted at the network level. | Invariant says its client removes passwords and secrets from configuration files before upload, and its cloud service uses encryption and environment isolation. |
| Support | GNS3 points users to its documentation and community for help, questions, and bug reports. | The contact page lists [email protected] for technical support and says Slack is the most immediate way to reach the company. |
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.
Invariant
Invariant validates network configurations against connectivity and security rules in a cross-vendor digital twin. It builds the model from configuration files, so direct access to routers or switches is not required. Users define policies in YAML and evaluate them against network snapshots, including proposed changes before deployment. Results can report policy violations and failures affecting critical flows. Scheduled network scans can trigger incident alerts with virtual traceroutes and virtual route-table differences. The service lists Cisco, Juniper, Palo Alto, and AWS among supported vendors, and integrations including Jenkins, GitHub Actions, LibreNMS, Netmiko, Aerleon, Capirca, IPAM, and SIEM workflows. A CLI, SDK, and API support automation. Listed protocols include BGP, OSPF, IPSec, NAT, policy-based routing, VPN, ACL, and VLAN. Invariant offers hybrid deployment and web/API access. The Basic account is free, billed as a free Basic account with effectively no usage limits. Higher tiers add SSO, larger device counts, and preview features.