Hello world! It has been quite a bit of time since I last wrote a post here. In my defense I have been insanely busy with family, work, and especially with planning my next SolarWinds NPM book. So on that note, let’s get straight to today’s topic – install GNS3 v1.4 on Windows 10.
What is GNS3?
GNS stands for “graphical network simulator 3”. It is emulation software that can run real-time Cisco IOS, JunOS, and other network OSes in a virtual environment (think virtual machines for network OSes such as Cisco’s IOS routers). GNS3 is very popular for those that create proof-of-concept networks for their own enterprise environments but it is also very popular for those training for the coveted Cisco certifications. It is important because GNS3 can be used in place of real hardware. As of the time of this writing the current GNS3 release is v1.4.0.
I am personally using GNS3 to help me with my next SolarWinds book. Plus it is just fun learning how to set up networks in a virtual environment. So lets get started!
This guide assumes you have at least an intermediate knowledge of networking and server administration.
- A Windows 10 Pro PC with at least 8GB RAM and Quad-core CPU.
** At the time of writing this post I’m using Windows 10 Pro build 10586.63 with 16GB RAM. (These instructions have not been tested on Windows 10 Home editions but it should work.)
2. VMware Workstation 12 Pro
Assuming you have VMware Workstation 12 Pro installed on your Windows 10 Pro PC, we can get started! Lets download the software we need:
- GNS3 v1.4.0
- GNS3 Virtual Machine OVA Image for VMware
- Cisco 3660 IOS image
Download the GNS3 software
Navigate to and log in (sign up for an account if you don’t have one). On the downloads page, note the links in the screenshot below. You need the Windows download as well as the GNS3 VM. Get both of them and save the files locally.
Get a supported Cisco IOS image
Cisco IOS images are downloaded from Cisco.com provided you are legally licensed for the software. Luckily I am legally licensed. For this example I am using the image c3660-jk9o3s-mz.124-25d.bin.
Import the GNS3 VM OVA into VMware Workstation
Before we GNS3 we need to import the VM image into VMware Workstation so it is ready to go.
- Launch VMware Workstation.
- Click File > Open
- Locate and select the GNS3 VM.OVA file, click Open.
- The Import Virtual Machine window will appear. Select the storage path and name for the VM (I’m using the default options). Click Import to finish.
The VM should now be imported and available. Leave VMW12 running (don’t close it) because GNS3 will automatically access the VM on-demand. We can now proceed with installing and configuring GNS3 on our PC.
Now that we have all of the prerequisite items, we can move forward with the installation.
- Launch the installer, click Next.
- Agree to the license terms, click I Agree.
- At Choose Start Menu Folder, click Next.
- At Choose Components, select ALL items and click Next.
- At Choose Install Location, define a location and click Install. **Default C:\Program Files\ is recommended.
- The WinPcap installer will appear. Click Next
- Click I Agree on the license terms.
- Make sure the check mark is selected to automatically start the driver at boot time. Click Install, then Finish
- The Wireshark installer will appear. Click Next, then click I Agree.
- Select all components then click Next.
- On Additional Tasks, click Next.
- On Choose Install Location, leave the default location and click Next.
- Remove the checkmark to install WinPcap (because we already installed it). Click Install.
- When Wireshark is installed, click Next then Finish.
- The SolarWinds Response Time Viewer installer will appear. Enter your email address then click Continue.
- Click Next,
- Accept the license terms, Click Next,
- At Choose Install Location, leave the default path then click Next, then Next again.
- Click Finish.
- The GNS3 software will finish installing on it’s own. Click Next when done.
- The “SolarWinds Standard Toolset” free license option appeared for me. I opted out of the free offer. I leave it up to you if you want it.
- Go ahead and click Finish to launch GNS3 for the first time.
Lets move forward with initial setup.
- The Setup Wizard will appear. Since we are using the GNS3 VM in VMware, choose the Local GNS3 VM option then click Next.
- Select VMware and the VM we imported. I recommend changing the vCPU cores to 2x and reducing the RAM to 2048 for now. Click Next to proceed.
NOTE: You can always increase the vCPU cores to 4x and increase the RAM at a later time if you plan on having a larger virtual environment. My personal configuration is shown in the screenshot below.
3. GNS3 will automatically start up the virtual machine in VMware. At Add Virtual Machines, check the box “Add an IOS router using a real IOS image” then click Finish.
4. Choose the GNS3 VM server type and click Next.
5. Choose your IOS image and click Next.
6. At Name and Platform, choose the appropriate options for your image and click Next.
Again, when in doubt just use the default option.
8. The next screen is where you define the default adapters that are added automatically when a new copy of this device is added to the GNS3 lab environment. Choose the adapters you want then click Next.
9. At the idle-pc finder, skip this section and just click Finish. (This can be done at a later time.)
10. The Preferences window will appear. Just click OK to close.
11. Create a new Lab name then click OK.
And that is it! GNS3 is now installed and working in VMware Workstation. If you open up VMware you should see the GNS3 virtual machine running and should look similar to the screenshot below.
Adding Your First Device to the Lab
Everything is now good to go. So lets go ahead and add in the first device and get it up and running!
Click the devices button, drag and drop the device into the lab pane, then click the Play button.
If everything is good, you’ll see the device status in green on the topology pane. Right-click the device and choose Console to open up the PuTTY console window to confirm.
From this point you should head over to the GNS3 community and start learning! Here is a direct link: .
There are also a bunch of additional how-to/example videos on YouTube for GNS3 so you’ll want to look there as well.
A few notes:
- Don’t close VMware Workstation when you have GNS3 open because it will shut down your virtual machines and cause GNS3 to crash.
- Don’t close GNS3 until you have saved your lab because GNS3 will automatically shut down the GNS3 VM in VMware Workstation when the app is closed. Also when you launch GNS3 it will automatically launch VMware Workstation and start up the VM. This is by design and is helpful so you won’t have to remember to start/stop the VM when launching or closing GNS3.
Well, that’s all I have for now. I’m still working on setting up my GNS3 and SolarWinds lab environments so maybe I’ll have more to write about soon. Have fun setting up your own labs!