[Solved] Connect GNS3 to Internet via Host Wi-Fi, Ethernet Adapter

By | June 24, 2014

Hi there, in my last articles we had covered Interfacing of GNS3 router to physical computer and Connect GNS3 to VirtualBox. Today I’m gonna to describe the sequential procedure to connect GNS3 to internet over host Wi-Fi adapter and over Ethernet adapter. There are many virtual networking tutorials available in the internet explaining the same. But all those describes with reference to Ethernet adapter. So I’m planning to connect GNS3 to internet via Wireless NIC adapter as well as Ethernet adapter. If you connect GNS3 router to internet over wireless adapter (Wi-Fi) it is very easy to realize virtual networks. GNS3 delivers a full featured virtual network simulator atmosphere for you.

The tutorial based on Windows platform since I’m a Windows user. So now let’s start our virtual network lab with GNS3.


Before You Begin

Connect GNS3 to Internet via Host Wi-Fi (wireless) NIC Adapter

Actually we are creating a Microsoft loopback adapter (virtual network adapter) and sharing the internet from Wireless NIC to the newly created loopback adapter by NAT (Network Address Translation) for virtual network computing.

Step 1: Setup Microsoft loopback adapter
In my last article I covered the complete procedure to set Microsoft loopback adapter. If you don’t know please read my last article.

→ Connecting GNS3 to Real Networks

Here I renamed the adapter to ‘LoopBack_NAT’ for simple identification.

Step 2: Configure NAT in Windows Networking and Sharing Center
Open Networking and Sharing Center, then right click Wi-Fi adapter → Properties.
In the Sharing tab check ‘Allow other network users to connect through this computer’s internet connection’ and then select appropriate loopback adapter that you like to share internet. I selected LoopBack_NAT which is the Microsoft loopback adapter that I created in step 1.
Once you click OK, the loopback adapter IP will change automatically to a static IP and you will see Wi-Fi shared in the Wireless NIC.
Step 3: Configure Cloud in GNS3
Open GNS3, and drag a cloud to workspace.

Double click on the cloud to configure, then select the required loopback adapter. For this reason I renamed my loopback adapter.

Step 4:
Now RUN the network simulation and configure the router as to receive DHCP.
Configuration commands are followed.

R1#conf t
Enter configuration commands, one per line.  End with CNTL/Z.
R1(config)#interface fastEthernet 0/0
R1(config-if)#ip address dhcp
R1(config-if)#no shutdown
*Jun 22 15:44:37.567: %LINK-3-UPDOWN: Interface FastEthernet0/0, changed sta                      te to up
*Jun 22 15:44:38.567: %LINEPROTO-5-UPDOWN: Line protocol on Interface FastEt                      hernet0/0, changed state to up
*Jun 22 15:44:55.019: %DHCP-6-ADDRESS_ASSIGN: Interface FastEthernet0/0 assigned DHCP address, mask, hostname R1

R1(config)#ip domain-lookup
*Jun 22 15:45:20.319: %SYS-5-CONFIG_I: Configured from console by console

R1#ping www.google.com

Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to, timeout is 2 seconds:
Success rate is 100 percent (5/5), round-trip min/avg/max = 148/162/184 ms

In order to ping public IP/ domain you have to enable IP domain lookup in the router.

So I used R1(config)#ip domain-lookup command in the configuration. Otherwise you can’t ping a public domain.

Connect GNS3 to Internet via Host Ethernet NIC Adapter

This is really simple procedure, no more NAT and loopback adapter! Directly we are bypassing the host Ethernet NIC to GNS3.


Instead of selecting loopback adapter in the GNS3 cloud choose the real Ethernet Network adapter.
All other things are just the same including the configuration.

That’s it; we have covered all basic stuffs in GNS3. Did you connect gns3 to internet windows 7?
My next article onwards I will share some advanced Cisco router configurations. Keep visiting SPT for more GNS3 and Cisco articles. If you liked this post please share to your friends and like our Facebook page to get more updates.

18 thoughts on “[Solved] Connect GNS3 to Internet via Host Wi-Fi, Ethernet Adapter

  1. Sid

    Thanks for the wonderful demonstration. I followed each and every step you mentioned . When I am configuring cloud I cannot find my loopback Adapter in the drop down list. Any Idea for the reason behind this. Thanks in advance.

    1. Admin Post author

      Hi Sid,
      Close GNS3, then create MS. LoopBack adapter, Make sure it is enabled. Now open GNS3 and configure cloud.


    2. ajay

      Run gns3 as administrator the u will definately find the loopback adaptor in the dropdown menu

  2. assistance_needed

    Ok, yesterday I installed and configured two loopbacks, one for host, other for wi-fi, CCP etc., everything worked and I was ready to set up ASA and run a lab. Today in the morning, Windows did an update that lasted an hour or more, with, as it wrote, new version of Windows 8.1. It took me through the re-installation process, but didn’t delete my data, except it deleted all created loopbacks including Virtual Box Host-only connection. I reinstalled and updated Virtual Box, connection works, but the two MS loopbacks work partially when connected in GNS3 1.1:

    Problem 1: when cloud (nio_gen etc. loopback that uses wi-fi for internet) and router (f0/0) connected, f0/0 does is not receiving dhcp address.

    Problem 2: when cloud (nio_gen etc. loopback that connect my host to the application) and router (f0/0) connected, i can ping successfuly from Command Prompt the f0/0, but ping from f0/0 to loopback fails.

    It seems that the Windows update returned everything to defaults, but I don’t see any changes in the firewall. Any fast solutions to this?

  3. assistance_needed

    Found where the problem is. Everything works when I shut down entire FW for public networks. It seems that the firewall now sees the loopback as an outer connection to the computer. Since I don’t have much experience with Windows FW, I would say that the loopback address should be entered as a permit inbound statement, as well as the other,, loopback, or rather, host and 20.0.0.x, but I don’t see an option for this currently. Any ideas how to make an exception for loopbacks in Windows FW?

  4. assistance_needed

    I found one solution for this, athough I don’t consider it optimal and secure. In System and Security open Windows FW, choose Advanced Settings, and in the opening screen, named Windows Firewall with Advanced Security on Local Computer option, there is an Overview section that lists Public, Private and Domain network (this can be opened also by right-click and properties selection in the left column on the row with the same name as the opening screen). At the bottom of the same section there is a Windows Firewall Properties button. Clicking it, it opens a Domain, Private and Public Profile settings, along with the IPsec Settings. Since the problem is located in Public network, choose Public Profile. When opened, profile lists a specification of behaviour for FW when connected to a public network. In the Firewall State section, there is a Protected network connections option that can be customized. Clicking the Customized button, it opens a list of all network connections present on the computer (loopbacks, wi-fi etc.). Then uncheck the loopbacks used for connecting the GNS3. Now everything works, and FW is still protecting other, main, connections. However, I would still like to find out what specific inbound or outbound rules should be applied to these loopbacks and keep the FW on them.

  5. Jusal


    Why I cannot add link from cloud to router? I only able to add link to other interfaces but not to loop-back I just created. I’m on windows 8.


  6. PeddyBro

    Great tutorial. I am having issues with pinging on to the internet. I can ping the PC and the the router interface but I cannot go to the internet. The router is resolving the host names but not allowing return traffic. If anyone has any ideas please share them. Thanks.

  7. Anil Kumar Nagaram

    It was really good and I was tired of making this connection live for quite long.

  8. Deven

    Hey there,

    I have configured my own lab following the above instructions. It has all worked fine and my Router1 can ping all web addresses (that means it is connected to internet.) However, I have connected Switch1 to my Router1 and is running on 192.168.100/24 network. LAN Interface(facing towards Switch1) for my Router1 is and another interface which has IP borrowed from DHCP is My switch can ping both ip addresses but cannot reach (which is Microsoft loopback IP). Hence, Switch1 and my VMs hanging off from it are not able to access internet. How can I make this work?


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