GNS3 is a Windows software for designing computer networks. It is oriented toward professional engineers. Users are able to run the service on a local machine or in a virtualized environment like VMWare or VirtualBox.

Getting started

This application allows you to construct, test and debug detailed network configurations. It is possible to browse all detected devices and connect them with each other. There are instruments for adding personal notes to the project. Moreover, you can draw lines and custom geometric shapes on the scheme.

Users are able to view the workspace grid for easier component placement. Detailed topology and server summaries are provided. A large library of network routers, switches and hubs is included. Every element can be further configured to better fit the project.

Emulation

Tools for testing custom network topologies. You can start all nodes and simulate traffic flow to detect potential bottlenecks, routing errors and inefficiencies. A console window with detailed connection information and operational logs is located at the bottom of the interface.

Features

free to download and use;
provides instruments for building and testing complex network topologies;
you can emulate the traffic flow to fix errors and eliminate bottlenecks;
there is a large library of supported routers, switches and hubs;
it is possible to add personal annotations to the project;
compatible with modern versions of Windows.