How to Install GNS3 on macOS/Mac

In this article, we will examine how to install and configure the GNS3 network simulator program, which is widely used to prepare for Cisco exams, in the macOS 12 Monterey operating system on an Apple Mac computer.

How to Install GNS3 on macOS/Mac

How to Set Up and Use GNS3 2.2.28 on macOS 12 Monterey

GNS3 is a network emulator/simulator program that is often used by network engineers or students preparing for Cisco exams. This software is a very powerful network simulator program compared to others and it is completely free.

You can use the GNS3 network simulator program on Windows and Linux operating systems, as well as on your Mac computer. If you are using a Windows operating system, you can install it on your computer by visiting this article.

After installing the network simulator program on your computer, you can now start preparing for your exams by creating network topologies and integrating IOS images of devices such as Cisco Router and Cisco Switch into the program.

How to Download and Install GNS3

To download the GNS3 software from the official website, you must first create a new subscription to the developer website. If you have an account, you can download this software for Windows, Linux, and Mac after login in to the website.

   Step 1

Visit the GNS3 website and click the Free Download button on its homepage.

Free GNS3 Download

   Step 2

You need an account to download the GNS3 software and join the community. If you have created a new account before, click Login.

Login to GNS3 Website

   Step 3

After typing your e-mail address and password, click Login.

Typing Account Information

   Step 4

Click the Download button again for the Mac version on the Download GNS3 page, and after downloading the DMG file, click on it and mount it to the system.

Download GNS3 for Mac

   Step 5

After mounting the DMG file, copy the GNS3 program by dragging and dropping it into Applications.

Copying GNS3 to Applications

   Step 6

Wait while the GNS3 software is copied to Applications.

Copying GNS3 Software

   Step 7

After copying GNS3, open Applications and run it.

Running the Program

   Step 8

Once the program is verified, allow to open it on your macOS system.

Allowing a Program to Run on macOS

   Step 9

uBridge needs root permission to interact with network interfaces. All admin users on your system will be able to read packages on these interfaces. Click Yes in the pop-up window to grant uBridge access.

Next, type your macOS user password to allow osascript to make changes while configuring the necessary settings and click OK.

Allowing uBridge

   Step 10

After the GNS3 network simulator program is opened, select the Run appliances on my local computer option in the Setup Wizard window and click Next.

Run appliances on my local computer

   Step 11

In the Local Server Configuration window, leave the server’s location, host binding value, and Port number at the default values and click Next.

Local Server Configuration

   Step 12

After checking the local GNS3 Server connection successfully in the Local Server Status window, click Next.

Local Server Status

   Step 13

Finally, check the settings in the Summary window and click Finish.

Summary of Local Server Information

How to Add Cisco IOS

After installing GNS3 on macOS, you need to add a Router ISO image that you downloaded to your computer. Because IOS images are not integrated into the program.

   Step 1

To add Router IOS, you need to open the program’s settings, so click GNS3 / Preferences.

Adding Cisco IOS

   Step 2

In the Preferences window, under Dynamips, select IOS Routers and then click the New button.

IOS Routers

   Step 3

Click Browse to add IOS in the New IOS Router Template window.

Selecting IOS Image

   Step 4

Select a Router IOS image that you downloaded to your computer from this link and click Open.

Adding the c7200 IOS Image

   Step 5

Click Yes to decompress the selected IOS image and wait.

Decompressing iOS

   Step 6

After verifying the location of the IOS image, click Next.

Verifying the Image's Position

   Step 7

In the Name and Platform window, leave the Router’s name, platform, and chassis settings at the default settings and click Next.

Name and Platform

   Step 8

Set the minimum amount of memory you want to allocate to IOS in the Memory window. If you set the memory value too low or too high, you may reduce the performance of your host computer or cause the Router to run slower. Therefore, leave the memory value at the default value set by the program and click Next.

Configuring Router Memory

   Step 9

In the Network Adapters window, you can add the interfaces you want to the empty slots of the Router. By default, only the C7200-IO-FE (FastEthernet) interface is available.

Adding a Network Adapter

   Step 10

In the Idle-PC window, you must specify a Router value to prevent 100% use of your host computer’s processor. Click the Idle-PC Finder button to set a value for the IOS you added and wait for the process to complete. Then, after a suitable value is found, click OK and click Finish to close the adding IOS window.

Idle-PC Value Determination

   Step 11

After checking the information of the C7200 IOS image you added in the Router Templates window, click OK.

Checking Router Information

How to Create a New Project

After adding the Router image to your GNS3 software, you can create a network topology by creating a new project by adding the Router or other components to your project.

   Step 1

After clicking New Project from the tool menu, type a project name in the Project window that opens and click OK after configuring the location you want to save.

Creating a New Project

   Step 2

Drag and drop the Router c7200 you added from the Devices panel to the workspace.

Adding the c7200 Router to the Project

   Step 3

Also, add one VPCS and connect it to Router.

Cabling VPCS with Router

   Step 4

Click the green arrow as shown below and then click Yes to start all devices.

Operating Network Devices

   Step 5

After running all devices, open the console by double-clicking on Router R1 and assign an IP address to the FastEthernet interface.

R1# conft
R1(config)# interface fastethernet
R1(config)# no shutdown

Assigning an IP Address to the Router's FastEthernet Interface

   Step 6

To give the VPCS device a new IP address, execute the commands below on the console, and then test the connection by pinging the R1’s FastEthernet interface.

PC1> ip

Giving an IP Address to VPCS

   Step 7

You can see that the connection between the two devices is OK when you execute the ping command on the console to ping the VPCS from Router R1.

Ping VPCS from Router

   Step 8

After creating and testing a simple project in GNS3, you can check the version of the program from the About section.

Verifying the Version of the Program

How to Completely Uninstall GNS3

When you need to uninstall GNS3 software from your Mac, you must first back up your projects and IOS images you have added. After this process, you can expand the disk space of your computer by completely removing GNS3 from your system.

   Step 1

Open Applications and right-click on GNS3, then click Move to Trash. Do not forget to empty the trash after deleting GNS3.

Uninstalling GNS3 from macOS

   Step 2

After removing GNS3 from your macOS system, residual files may remain on your system, so you can open the terminal on your system and use the mdfind gns3 command to find and delete these files.

mdfind gns3
sudo rm -rf '/Users/macOS/GNS3'

Deleting Relic Files of the Program


Installing Old Versions

YouTube Video
macOS Monterey (New)
macOS Mojave
macOS High Sierra
macOS Sierra


   Related Articles

How to Add Layer 2 Switch to GNS3
How to Add Layer 3 Switch to GNS3
Understanding Spanning Tree
How to Configure Cisco Switch Basically
How to Install Cisco IOU

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