how to use virtualBox VM with GNS3 1.1 | VM Lab

How to use VirtualBox Virtual Machine in GNS3 as Virtual Host in GNS3 Topologies:

You have different options for simulating Virtual PC on GNS3 which are listed below:

In all above methods, simulating a PC with VirtualBox is very handy which provide you more options as compare to others. In-fact you have a real PC with operating  system of your choice with full control.
In this article i will show you how to use Windows 7 VM with GNS3. Following are the step by step process of configuring VM in GNS3:

1. Create or install any virtual machine in VirtualBox. I already have an installed VM i.e. "Win 7" so i will use this for lab.
2. Now open the GNS3 1.1 and go to Edit\Preferences and from VirtualBox VMs menu create a new VM by clicking the New button.

3. Select the desire Virtual Machine from next menu, i am selecting the only created VM "win 7" and then click finish.
4. Once you finished, you can find your VM in GNS3 devices.

5. Drag the "win 7" VM on Dashboard, i have created the following topology with this VM.
6. Right click on VM and click start, GNS3 will start booting Windows 7 with help VirtualBox. Once it is booted, now you can configure IP address for it. Open local area connections properties and double click on internet protocol version 4

and assign the IP address and gateway.

Watch a Video how to use VM on GNS3

how to use or configure virtualBox VM with GNS3... by Waqasgk

Nat Sim for ICND2 Practice lab on GNS3

Your company has 14 PCs those need to access the internet simultaneously. All the computers in the local area network are using the private IP addresses from to
  • Configure serial s0/0 as NAT outside
  • Configure serial f0/0 as NAT inside
  • You need to configure NAT (network address translation) on PE-router with 4 public IP addresses from to so that all the hosts can use internet at the same time.

Note: Since we are creating this lab on GNS3 therefore we are using private IP addresses i.e. 192.168.1.X for NAT translation instead of real Public IPs. Please keep in mind that in real scenario you must use Public IP addresses. 
For configuring this lab on GNS3 1.1 i have used the following devices:

IOS: c7200-jk9s-mz.124-13b.image
Router full configuration: PE-Router configuration

I have used cloud for internet connectivity with my laptop Ethernet interface, i also recommend you to use physical local area connection of your PC with gns3-cloud instead of wifi-adapter, you learn how to use cloud in GNS3 from here.

VPCS (Virtual-Host):
IP adress=
You can learn how to configure IP address and Gateway of VPCS on gns3 from here.


1.Configure serial f0/0 as NAT inside 

config t
Router(config)#hostname PE-router
PE-router(config)#interface fa0/0 
PE-router(config-if)#ip nat inside 

2.Configure serial s0/0 as NAT outside

PE-router(config)#interface s0/0 
ip nat outside 

3.Configure NAT ON Router:

In second step you need to configure pool of Public IP addresses, you can do it by using following commands:
PE-router(config)# ip nat pool LIVEIP-POOL netmask

Now create an access-list for private IP addresses and permit all hosts.
PE-router(config)#access-list 1 permit
Now apply this access-list with NAT, following command will pick up IP address from to and with map it to LIVEIP-POOL ( to
“Overload” keyword allows to map multiple IP addresses to a single registered IP address by using different ports.
PE-router(config)#ip nat inside source list 1 pool LIVEIP-POOL overload
Save all configurations;
PE-router#copy run start
 Ping or some internet address like and then see the nat translations using "show ip nat translations"
PE-router# show ip nat tran

Configure VPCS IP address and Gateway on GNS3 1.1

How to use VPCS in GNS3 and how to configure IP address and Gateway for it:

VPCS is virtual PC simulator that is now included in GNS3 devices. You can use it for testing purposes on GNS3, you can ping, traceroute etc with VPCs on GNS3.
VPCs is already included in GNS3 1.1 and some earlier versions and also you don't need to perform any additional setting for it. In following figure you can find the default settings of VPCs on GNS3 1.1, which normally works great..!

how to simulate PC with VPCs on Gns3:

Drag the VPCS from end-device on Gns3 dashboard, right click on it and then on start.

It will boot in few seconds. For configuring IP address and gateway right click on VPCS and then on console.  You can use the following command for configuring IP address and gateway for this virtual PC.

IP <address> [/<mask>] [<gateway>]

For example if you want to assign IP address "" with subnet-mask and gateway "" you will use the following command:

PC1> ip /24

For connectivity test you can use ping command

Following are some other ways of simulation of Host or PC with GNS3