GNS3 vs OMNeT++

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.

OMNeT++ is a modular C++ simulation library and framework used mainly to build network simulators. Its discrete-event models consist of communicating C++ modules whose structure is defined in the NED language. Simulations can run in Qtenv, a graphical runtime environment, or Cmdenv, a command-line interface. The IDE Analysis Tool uses Pandas and Matplotlib to analyze and plot results; R and Matlab can also process them. Extensions cover real-time simulation, network emulation, database integration, and SystemC integration, while the INET model library provides Internet stack models and other protocols and components. Packages are offered for Linux, Windows, and macOS, along with a core archive and container images. The project recommends opp_env for installation and uses WSL in its recommended Windows route. Its Academic Public License allows noncommercial teaching and research; commercial work requires a separate license, priced on request. The maker says the software has no telemetry or account system and keeps models and results on the user's computer.