How to Install Cisco IOU on GNS3 VM

You can gain experience by designing network topologies on GNS3 or use IOS images of real Cisco devices. By adding IOU devices to your network project, you can use the Cisco Layer 2 Switch and Layer 3 Switch.

How to Install Cisco IOU on GNS3 VM

How to Add IOU to GNS3 Server

You can easily use real Cisco Switch IOS in the GNS3 program. However, in order to fully utilize the Switches you add, you need to use IOU (IOS on Unix/Linux).

What is Cisco IOU?

First of all, let me briefly explain what IOU (IOS on Unix) is.

IOU stands for IOS on Unix / Linux. In short, they are Cisco IOS images running on Unix and Linux operating systems.

IOU functions are similar to Dynamips but use fewer resources. While Dynamips simulates the Cisco Router and Switch devices, you can add the same devices in the IOU structure.

In addition, as this structure is designed by Cisco employees for experimental purposes, it is strictly prohibited to distribute and reproduce these images to customers or any platform.

The biggest advantage of using this image is the ability to design more complex networks than Dynamips. In addition, the GNS3 VM virtual machine installed on an external drive provide more performance.

Additionally, you don’t have to fill your computer’s disk capacity with Cisco images and GNS3 projects.

Our recommendation; Inserting a high-speed SSD drive into the USB 3.0 external drive box makes it healthier and more efficient to use.

What is GNS3 VM?

In the early stages, GNS3 only simulated Cisco IOS images with Dynamips. Together with the development of the program, they provided for a solution due to Dynamips’ high resource usage while creating network designs and running GNS3 Server on the virtual machine, resulting in less resource usage.

How to Add and Run IOU Images on GNS3 Server

After briefly discussing what is IOS on Unix and GNS3 VM, let’s examine how to upload and use an image onto the server.

   Step 1

Once you have the necessary tools, the first thing you do is to install the GNS3 VM. Double-click the setup file to start the installation.

Running the GNS3 VM Setup File

   Step 2

After running the VMware Workstation program, click the Import button to add the GNS3 OVA file to the virtual machine.

Import Virtual Machine

   Step 3

Please wait while importing the GNS3 VM OVA file.

Importing GNS3 VM

   Step 4

Once the GNS3 OVA added to the virtual machine, run the VM.

Running the GNS3 Virtual Machine

   Step 5

The first boot view of the GNS3 VM server is as follows.

Opening the GNS3 Server

   Step 6

Opening GNS3 Server …

Ubuntu 14.04 LTS

   Step 7

Make a note of the IP address of the server and press the Enter key on the OK option to switch to Advanced Setup.

Viewing Advanced Settings

   Step 8

On the Shell (Open a console) option, press Enter.

Shell / Open a Console

   Step 9

You will need a license file to upload an IOU image to the GNS3 server.

Since the distribution of IOU images is prohibited, we have hidden some points during the licensing process.

Run the following commands to check the presence of the license file in the GNS3 Server root folder. If there is no license file, go to the next step.

gns3@gns3vm:~$ sudo su
root@gns3vm:/home/gns3# ls

gns3@gns3vm:~$ sudo su

   Step 10

To access the GNS3 VM root folder, open the WinSCP program, type in the IP address of the server, type gns3 in the user name and password, and click Login.

Using WinSCP

   Step 11

Click the Yes button on the security alert of the WinSCP program.

Confirm Connection to Server

   Step 12

Drag and drop the file to the /home/gns3/root folder.

Root Folder of GNS3 Server

   Step 13

Click OK to complete the process.

Copying the License File

   Step 14

After copying to the GNS3 VM root directory, continue to the next step.

Copying the License File

   Step 15

Execute python3 at the Shell command prompt of the GNS3 VM. Then, add the generated license number to the iourc.txt file.

Generating a License Key

   Step 16

Create a text document named iourc.txt on your desktop, then write the license and save the file.

Editing an IOURC File

   Step 17

Copy the iourc.txt file you created to the location where you installed the GNS3 VM.

Copying IOURC to GNS3 VM

   Step 18

After running GNS3, select Local GNS3 VM and click Next.

Local GNS3 VM

   Step 19

On the next screen, select VMware (Recommend) to continue. In this step, it will connect to the GNS3 Server automatically.

VMware (Recommended)

   Step 20

Connecting to GNS3 Server …

Connecting to Server

   Step 21

Before adding the IOU image on GNS3 Server, close the Add Virtual Machines window.

Add Virtual Machines

   Step 22

Click Edit / Preferences to complete the licensing process.

GNS3 / Edit / Preferences

   Step 23

In the window that opens, select IOS on UNIX and click Browse to add the iourc file in the right pane.


   Step 24

Select the iourc.txt file you copied to the GNS3 server location and click the Open button.

Opening the IOURC File

   Step 25

After adding the iourc file, click Apply to save the settings.

IOS on Unix

   Step 26

Click IOU Devices and then click the New button to add Layer 2 and Layer 3 Switch.

GNS3 Devices

   Step 27

In the Server Type window that opens, select the Run this IOU device on the GNS3 VM option and click Next.

Run this device on the GNS3 VM

   Step 28

Enter the Layer 2 Switch name you want to add, and then click Browse. In the Type field, specify the Switch layer.

Name and Image

   Step 29

Select and add the Layer 2 Switch image.

Selecting the Layer 2 Switch's IOS Image

   Step 30

After adding Layer 2 Switch, click Finish.

New IOS on Unix Template

   Step 31

Once you have successfully added the Layer 2 Switch as in the image below, add an L3 Switch by clicking the New button again.

Device Template

   Step 32

Click Next in the Server Type window.

Server Type

   Step 33

Type Layer 3 Switch name and specify the type. Then click the Browse button to add the IOS image.

New Image

   Step 34

Uploading Layer 3 Switch into GNS3 Server.

Uploading Switch Image

   Step 35

Click Finish to upload the image to the server.

Name and Image

   Step 36

Close the IOU Device Templates window after adding L3 Switch.

Closing the IOS on Unix Window

   Step 37

Add the L2 and L3 Switch to the GNS3 workspace and run them.

Connecting Two Cisco Switches

   Step 38

In the L2 Switch console window, test the device’s operability by creating one VLAN as an example.

Creating a New VLAN

   Step 39

When you execute the show vlan command on the L2 Switch, you can see that a new VLAN created.

show vlan

How to Configure IOS on Unix on GNS3 ⇒ Video

To use IOU images with GNS3, you can watch the video below and also subscribe to our YouTube channel to support us!

   Final Word

In short, running IOU IOS images on GNS3 Server is more efficient. The use of these images is a major requirement for studying CCNP or CCIE exams. Thanks for following us!

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