GNS3 is open-source software that helps in emulating networks using the Cisco Internetwork Operating Systems (IOS). GNS3 enables you to run a Cisco IOS in a virtual environment and serves as a graphical user interface to Dynamics. For some articles I have written on GNS3, please see the following guides “Error–Failed to open a session for the virtual machine GNS3 VM, how to make a router function as a switch in GNS3 and Graphical Network Simulator: How to connect GNS3 to the internet on Windows. When it comes to network simulators and emulators, everyone has their favorite. In this article, I will be discussing the Graphical Network Simulator (GNS3).

In subsequent articles, I will be discussing other simulators and emulators listed belo.
– Packet Tracer
– EVE-NG
– Boson NetSim
– GNS3
– VIRL

How to install GNS3 on macOS

Note: Download GNS3 at the following using the following link. Furthermore, You will be asked to log in to the GNS3 account.
– However, If you haven’t created an account previously, please do so and continue with the download. Moreover, This will prompt the download page as shown below. Since we are installing GNS3 to a macOS, we will click on download under mac as shown below.

This will download the GNS.dmg file as shown below. Just double click on the downloaded file

Click on the downloaded DMG and drag the GNS3 icon to the Applications folder

This will start the process of copying "GNS3" to macOS Applications as shown below. Make sure GNS3 is installed in “Applications” to avoid any problem. It has been reported that the application may crash if launched from a path containing non-ascii characters.

Since GNS3 is distributed outside the Apple App Store and downloaded from the web, you need to allow the installation by clicking on open.
– This is required only at first launch. The next time you click on GNS3, the application will start normally as Mac OS will remember the configured security settings.

Once GNS3 starts, you will be prompted to allow root uBridge. This is required to allow GNS3 to control your network.
– Click on “Yes” as shown below:

Upon clicking on Yes on the above screen, you will be prompted to enter your credential in order for GNS to be able to make the needed changes.
– The commands will be executed as shown below