How to Install Cisco IOU L2 Appliance in GNS3

In our previous articles, we examined the steps of adding a Layer 2 Switch to the GNS3 program. In this article, we will examine how to add the Cisco IOU L2 IOS image.

How to Install Cisco IOU L2 Appliance in GNS3

How to Setup Cisco IOU L2 Appliance on GNS3

GNS3 is a continuously developed network emulator program. And those who prepare for the Cisco exams are more likely to use the GNS3 program. The biggest advantage of using this software is that it is free. Furthermore, many detailed network designs can be designed and run on it.

Many people had problems with using Cisco Switch on GNS3. With the Appliance structure, it is now easier to install and use the network device.

In order to use Cisco IOU images in the GNS3 program, GNS3 VM Server must be installed. Otherwise, you will not be able to install the IOU.

In addition, you can check out our articles on How to Import GNS3 VM and How to Make the GNS3 VM Network Connection.

How to Add IOU to GNS3

In order to use Layer 2 Switch, you need to download the necessary IOS image and import it with this application. You can find the IOU L2 Appliance installation file at the end of the article.

To import the IOU image, follow the steps below.

   Step 1

After you download the Cisco IOU L2.gns3a file to your computer, double-click it.

Opening the L2.gns3a File

   Step 2

After opening the program, you will be informed about the IOU L2 installation. You can see that Layer 2 Switch is in the Multilayer Switch category.

To import GNS3 Appliance, click Next.

Add Appliance

   Step 3

Select GNS3 VM Server for installation and click Next.

Run the Appliance on the GNS3 VM

   Step 4

The files required for the IOU are as follows. You can update the files to be downloaded by pressing the Refresh button. Select the existing Cisco IOU L2 15.2.d file (i86bi-linux-l2-adventerprisek9-15.2d.bin) and check if the GNS3 VM Server is running before clicking Next.


   Step 5

GNS3 VM Server is currently running in the background.


   Step 6

You must have the L2 image in the Required Files window. The distribution of these images is strictly prohibited and you can do research on the Internet to download them.

After downloading the IOU image, click Next to load the selected image.

IOU L2 15.2d

   Step 7

Do you want to install version 15.2d? Continue by clicking Yes.

Confirm Loading IOS Image

   Step 8

The hardware specifications for the Appliance that will run on the GNS3 VM are as follows.

Add Appliance / Summary Window

   Step 9

When importing, the new device is reported to be in the Multilayer Switch category.

The appliance is available in the Multilayer Switch category.

   Step 10

After you have successfully completed the IOU installation, click OK.

IOU L2 Installed

   Step 11

Create a new project in GNS3 to check the added image.

Creating a New Project on GNS3

   Step 12

As you can see in the image below, Layer 2 Switch with 15.2d image is available in the tools menu. Drag and drop the switch into the workspace.

GNS3 / All Devices

   Step 13

At the CLI prompt, execute the show version command and check the system image and installation location of the Layer 2 Switch.

As you can see, the L2 Appliance has installed successfully!

Operating the IOU

   Step 14

You can check the interfaces of the switch by running the show ip interface brief command on the switch.

show ip interface brief

   Step 15

Create a new VLAN to verify the functionality of the IOU image and run the do show vlan command in config mode to verify the VLAN configuration.

Creating a New VLAN

Show Commands

IOU1#show version
Technical Support:
Copyright (c) 1986-2015 by Cisco Systems, Inc.
Compiled Wed 04-Nov-15 02:31 by mmen

ROM: Bootstrap program is Linux

IOU1 uptime is 2 minutes
System returned to ROM by reload at 0
System image file is "unix:/opt/gns3/images/IOU/i86bi-linux-l2-adventerprisek9-15.2d.bin"
Last reload reason: Unknown reason

This product contains cryptographic features and is subject to United
States and local country laws governing import, export, transfer and
use. Delivery of Cisco cryptographic products does not imply
third-party authority to import, export, distribute or use encryption.
Importers, exporters, distributors and users are responsible for
compliance with U.S. and local country laws. By using this product you
agree to comply with applicable laws and regulations. If you are unable
to comply with U.S. and local laws, return this product immediately.

A summary of U.S. laws governing Cisco cryptographic products may be found at:

If you require further assistance please contact us by sending email to

Linux Unix (Intel-x86) processor with 158154K bytes of memory.
Processor board ID 2048001
16 Ethernet interfaces
1 Virtual Ethernet interface
16K bytes of NVRAM.

Configuration register is 0x0



IOU1#show vlan

VLAN Name Status Ports
---- -------------------------------- --------- -------------------------------
1 default active Et0/0, Et0/1, Et0/2, Et0/3
Et1/0, Et1/1, Et1/2, Et1/3
Et2/0, Et2/1, Et2/2, Et2/3
Et3/0, Et3/1, Et3/2, Et3/3
10 IT active
1002 fddi-default act/unsup
1003 token-ring-default act/unsup
1004 fddinet-default act/unsup
1005 trnet-default act/unsup

VLAN Type SAID MTU Parent RingNo BridgeNo Stp BrdgMode Trans1 Trans2
---- ----- ---------- ----- ------ ------ -------- ---- -------- ------ ------
1 enet 100001 1500 - - - - - 0 0
10 enet 100010 1500 - - - - - 0 0
1002 fddi 101002 1500 - - - - - 0 0
1003 tr 101003 1500 - - - - - 0 0
1004 fdnet 101004 1500 - - - ieee - 0 0
1005 trnet 101005 1500 - - - ibm - 0 0


Primary Secondary Type Ports
------- --------- ----------------- ------------------------------------------



IOU1#show running-config
Building configuration...

Current configuration : 1361 bytes
! Last configuration change at 07:43:44 UTC Mon Sep 18 2017
version 15.2
service timestamps debug datetime msec
service timestamps log datetime msec
no service password-encryption
service compress-config
hostname IOU1
logging discriminator EXCESS severity drops 6 msg-body drops EXCESSCOLL
logging buffered 50000
logging console discriminator EXCESS
no aaa new-model
no ip icmp rate-limit unreachable
no ip domain-lookup
ip cef
no ipv6 cef
spanning-tree mode rapid-pvst
spanning-tree extend system-id
vlan internal allocation policy ascending
ip tcp synwait-time 5
interface Ethernet0/0
interface Ethernet0/1
interface Ethernet0/2
interface Ethernet0/3
interface Ethernet1/0
interface Ethernet1/1
interface Ethernet1/2
interface Ethernet1/3
interface Ethernet2/0
interface Ethernet2/1
interface Ethernet2/2
interface Ethernet2/3
interface Ethernet3/0
interface Ethernet3/1
interface Ethernet3/2
interface Ethernet3/3
interface Vlan1
no ip address
ip forward-protocol nd
no ip http server
no ip http secure-server
line con 0
exec-timeout 0 0
privilege level 15
logging synchronous
line aux 0
exec-timeout 0 0
privilege level 15
logging synchronous
line vty 0 4



How to Use the Appliance Feature in GNS3 ⇒ Video

You can watch the video below to use Appliance on GNS3 and also subscribe to our YouTube channel to support us!

   Final Word

In this article, we have added a new Layer 2 Switch on GNS3 VM Server. If you want to add an L3 Switch, you can take a look at Adding Layer 3 Switch in GNS3. The use of GNS3 VM Server is crucial to performance. We also recommend that you install GNS3 VM on an external disk. In addition, we strongly recommend using an external SSD disk. Thanks for following us!

   Related Articles

How to Add Router to GNS3 VM
How to Update GNS3 VM
How to Add Loopback Adapter in GNS3
How Switch Works?
How to Configure VPCS in GNS3

   IOU L2 15.2d Download

You can download the IOU L2 image file from the button below.

Download File

  1. Peifei 10 February 2020

    Hello,It’s coll!
    My question is, where can I find the file Cisco IOU L2.gns3a?

    • Tolga Bagci 11 February 2020

      We cannot share these IOU images because it is strictly forbidden to distribute them. But maybe if you research on Google, you might find it.

Add a Comment

Your email address will not be published. Required fields are marked *