How to use switch in gns3 | switching labs in gns3 1.1

How to run a switch in Gns3:

In this article I will show you how to use Cisco switch in Gns3 1.1 and Gns3 0.8 virtualbox edition. You can perform switching functionality on GNS3 simply by using NM-16ESW module. This module is normally available or work with Cisco 3600 & 3700 series. Using NM-16ESW you can configure switching protocols like VLAN, STP, VTP on gns3 ect. 

Cisco Commands For Beginners

How to use Switch in Gns3 1.1:

Open Edit \ Preferences\ dynamips\IOS Router & click on new button.

Browse the Cisco 3600 & 3700 series image and click next.

Type it’s name and set a suitable RAM for it.

The next step is most important one, where you need to define NM-16ESW, you can choose it from drop down menu.

In next step, set the idle PC value for your router and finish this wizard.

After this you will find your router with switching functionality in Gns3 device menu.

You can drag it to gns3 stag and connect it via NM-16ESW module with other devices and you can try some switching commands that are mention at the end of this post.

How to use Switch in gns3 0.8 virtualbox edition:

  • First open the "Symbol Manger" from Edit tab.
  • Add a ethernet_switch from  available symbol to customize nodes. Type a name for switch and in Type field assign the Cisco router IOS to switch, in my case i select the  c3600 series and i have used IOS c3640-jk9o3s-mz.124-16a (33MB). You can download switch IOS for GNS3 from this link.

  • Click on apply and then on ok button.
  • Now you can find a new switch in nodes types.

  • Now drag this switch on stage and click on configuration and add  NM-16ESW module from slot tap.

  • click on OK you may received a message "You must use 'manual mode' to connect a link with a NM-16ESW module". Therefore use the manual method to configure this.

How to add switch image in GNS3 1.1

For gns3 1.1 open the edit\preferences, then explore the dynamips tab and click on "ios routers". now click on new and browse the above downloaded image, click next. 

Type name for router and click next. Now from slots tab choose the NM-16ESW for switching function and click finish.

Switching labs in gns3 

Now for test i shall configure two vlan on switch. For Vlan configuration you can use the following commands.
vlan database
vlan 10
vlan 20

  • Start your switch and try these commands also can see in screen-shot for vlan 10, 20.

For complete switching labs visit following posts of blog.   

1. Switch virtual interface SVI configuration on gns3 
2. Inter VLAN on gns3 
3. Hot Standby Router Protocol configuration on GNS3

You must use 'manual mode' to connect a link with a NM-16ESW module

Last nigth I am trying to emulate a swithing module, so I have have use NM-16ESW. But when i check for the NM-16ESW moduled interfaces, I do not see NM-16ESW in command line.

 I also try the manual connection but not able to find this module.
After a lot of experiment i have come to know that this is an IOS problem i have tried
  • c2600-i-mz.123-22
  • c7200-jk9s-mz.124-13b
  • c3700
but none of above is working correctly with  NM-16ESW module.

then i try c3640-jk9o3s-mz.124-16a (33MB), its working fine with NM-16ESW module.
so if you also have the same problem then try this IOS and please feedback me...

How to add Qemu host in Gns3 1.1 | IP and gateway configuration

The most simple way of simulating a PC in Gns3 with Qemu host or using Tinycore Linux. In this article we will see how to run qemu host in Gns3. If you want to learn more about GNS3 pleae visit "how to use GNS3 1.3"

How to use Qemu on Gns3 1.1:

you can add qemu host in gns3 with following steps:

  • Download qemu-img for gns3, you can find a link for download in bottom of this post.
  • Open Gns3 1.1 and navigate to Edit \ Preferences \ Qemu \Qemu VMs and click on new button.

  • A will new wizard will be start, define name, image-path and RAM and finish the wizard.
  • Once you done you will see qemu PC in Gns3 devices.  

How to add Qemu on Gns3 0.8.X

GNS3 0.8.X shows error "Please configure a Qemu host" when there is no default IOS image set for qemu, to resolve this problem click on Edit/Preferences. You need a IOS image foe qemu host that you can download free from internet. Then click on Qemu\qemu tab and define the "identifier name" and binary image location and then click on save button.
 IOS image configuration for Qemu host is completed.
how to configure IP and default gateway for qemu host:
  • Now insert a "qemu host" and router on topology area rigth click on host then click on start a console is appear wait to complete the loading. after some time console appear as shown in figure, now you can configure the qemu host. 

  • For IP and default gateway configuration use the following commands. 
tc@box:$ sudo su 
Configure IP For Qemu: root@box:$ Ifconfig eth0 netmask
Configure GW For Qemu: root@box:$ Route add default gw eth0

you can download Qenu IOS image from here, for more information you can ask any question thanks for visiting.

Following are some methods for simulating PC on GNS3

    Connect GNS3 router to internet

    How to Connect your GNS3 router to internet:

    Hi today I shall show you that how to connect a GNS3 router to internet, this lab is handy for practicing NAT, PAT and default gateway on GNS3. With this you can create a live environment on GNS3. So please follow the steps to accomplish this   

    • First you need to configure your gns3 cloud, insert a cloud from left menu “GNS3 devices” panel and then right click on cloud/configure and add your physical NIC.


    • Now insert a router which you want to connect to internet, connect this router to cloud via Ethernet/FE according to your NIC and start all devices.

    •   Now you need to assign an IP address to your router interface that is connected to cloud (e1/0 in my case). IP of interface should be of the same subnet as of your NIC, in my case my NIC subnet is therefore I assign to e1/0.
    •  Now you need to create a default route for internet. Default gateway in my case is you can check yours by clicking NIC status/Details. 

    • Now ping any Public IP e.g. to verify this.