How to set up GNS3 server on VMware ESXi?


Imagine having the power to create, experiment, and test the SONiC networks without needing any physical equipment or worrying about mistakes πŸ€” That's where GNS3 comes in – your gateway to the thrilling realm of virtual networking. In this article, we'll walk you through the fundamentals of GNS3 using a unique setup: a pre-configured virtual machine with GNS3 all set up and ready to go. This means you can jump right into networking without the hassle of dealing with complex installations πŸš€πŸ˜‰

Optimal Hardware Requirements

Ensure that your system meets the following requirements for an optimal GNS3 experience, especially if you plan to work with complex network setups and simulations.

  • Processor: You'll need a powerful processor for the best experience. We recommend an Intel Core i7 or i9 CPU, an AMD Ryzen 7 (R7) or Ryzen 9 (R9) CPU, or any CPU with 8 or more logical cores. Make sure your CPU supports virtualization technologies like AMD-V (RVI Series) or Intel VT-X (EPT).

  • RAM: To run GNS3 smoothly, you should have at least 32 GB of RAM. More RAM can further enhance performance, especially when dealing with complex network simulations.

  • Free Hard Disk Space: GNS3 operates best with a solid-state drive (SSD) that offers at least 80 GB of available space. SSDs provide faster data access and improve overall performance.

  • Graphics Card: While not a top priority for GNS3, a graphics card with dedicated VRAM and support for OpenGL 3.0 or newer is recommended. This helps with graphical rendering and user interface responsiveness.

  • Internet Connection: A fast and stable internet connection is essential if you plan to download additional device images or use cloud-based resources within GNS3.

  • Operating System: GNS3 is compatible with various operating systems. You can run it on Windows 10, macOS 11 or newer, or supported Linux distributions. Ubuntu 20.04 or later is a recommended choice, but it can also work within other virtualization environments.

  • Additional Considerations: Keep in mind that running virtual devices can be demanding on your processor and memory. While meeting the minimum requirements is essential, a well-configured network device often matters more than having the most powerful hardware.

  • ESXi Version: This documentation covers only ESXi 8.0 using the web interface. The GNS3 VM is known to work with ESXi 5.5 to 7.0 but the configuration interface will be different. The vSphere UI is also not explained here.

Step 1: Download the Pre-Built GNS3 Virtual Machine

Before we dive into setting up GNS3, let's start by downloading the GNS3 Virtual Machine (VM). This VM comes pre-configured with GNS3, making the setup process much smoother.

You have two download options for the GNS3 VM. In this step, we'll explain both choices, so you can pick the one that fits your needs perfectly.

Option 1: Download via GNS3 Website (Recommended)

  1. Go to
  2. On the download page, select the VMware ESXi option.

Dowload GNS.png

Option 2: Download from GitHub (Alternative)

  1. Visit the GNS3 release page on GitHub at
  2. On the release page, you have the option to download the GNS3 application, various versions of the GNS3 VM, and even access the source code.

Dowload GNS_github.png

Once you've downloaded the GNS3 VM, you'll get a .zip archive. It's crucial to unzip or extract its contents before proceeding to import it into your ESXi.

Step 2: Import the Virtual Machine into VMware ESXi

  1. Launch ESXi page on your web browser.
  2. In ESXi, select Create/Register VM.

    import vm.png
  3. In the dialog box that appears, check "Deploy a virtual machine from an OVF or OVA file" and click next.

  4. Select or drag the unzipped .ova image file into the blue box and enter the VM name.

    select.png select.png
  5. Select the datastore of your choice and continue.

  6. Change the VM deployment options.

  7. At the end of wizard wait for disk upload to finish.


Step 3: Configure the Virtual Machine Parameters

Once you've imported the GNS3 VM, it's crucial to configure its parameters to guarantee optimal performance for your network simulations.

    1. In the ESXi homepage, select Networking from the list on the left-hand side and choose Add port group.

    2. Enter the name GNS3 then expand the security tab and check all the accept boxes as in the picture.

    3. Go to the ESXi home page, select the imported VM and go into settings.

      change specs.png
    4. In the settings window, make sure to allocate the recommended amount of RAM and CPU cores according to the optimal hardware requirements stated in the introduction.
      • Set the amount of RAM and CPU cores and select the network adapter you created earlier.

      • Expand the CPU tab and make sure that hardware virtualization is selected as shown in the picture.

        change specs.png


It is important that hardware virtualization is enabled without this GNS3 will not work properly.

Step 4: Starting the GNS3 VM on VMware ESXi

  1. In ESXi home, locate the GNS3 VM in the left sidebar. It should be listed with the name you provided during the import process. Select the GNS3 VM to highlight it, then click the Power on button in the ESXi toolbar.

  2. ESXi will initiate the boot process for the GNS3 VM. You will see a console window showing the VM's boot progress.

  3. Once the GNS3 VM is fully booted and ready, you'll see information on how to access the GNS3 graphical user interface (GUI). Typically, this information includes an IP address or hostname that you can use in your web browser. Make a note of this access information, as you'll need it to log in to the GNS3 GUI in the next steps.

  4. Launch your browser and open the specified IP address. This will take you to the GNS3 interface where you can manage your network simulations.

    new project.png


Well done! With GNS3 up and running on VMware ESXi and SONiC at your fingertips, you're fully equipped for thrilling network simulations and valuable learning experiences. Dive into the world of virtual networking with GNS3 and SONiC and enjoy the exciting possibilities ahead! Happy networking! πŸ˜„πŸŒπŸš€

If you're looking for more GNS3 tutorials and resources, you can explore the following articles:

How to set up GNS3 server on VirtualBox?

How to create a new GNS3 appliance template to work with SONiC using GNS3 Desktop Client?

How to create a new GNS3 appliance template to work with SONiC using GNS3 Web UI?

How to create a new GNS3 appliance template to work with SONiC using Linux shell?

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