How to Add Loopback Adapter on GNS3 in Windows 10 or 11

In today’s world, network simulation is critical in the IT industry. GNS3 is a tool lots of engineers and IT folks use. It helps you make pretend networks with routers, switches, and virtual machines. But if you’re using it on Windows 11 or 10, you need to add something called a “loopback adapter” to make it work smoothly.

This guide will show you exactly how to do that in simple steps. It’s easy to follow and will get you this card installed without any trouble.

Configuring Loopback Adapter in GNS3

Credit: Microsoft

How to Add a Loopback Adapter for GNS3 on Windows 11 / 10: A Step-by-Step Guide

If you’re having trouble with GNS3 on your Windows 11 or 10 PC, add something called a Loopback Adapter to make it work better. This virtual card is like a unique tool that helps your laptop pretend to have network traffic. Setting it up can be tricky if you’re not used to it.

But don’t worry! This guide gives you simple, step-by-step instructions to make the whole process easy. It covers everything from getting the correct files to setting up the interface. With this guide, you’ll have this virtual interface installed and your GNS3 program running smoothly in no time.

Why is a Loopback Adapter Necessary for GNS3?

To use GNS3, a network simulator, on Windows OS, you need to have a Loopback Adapter installed. This is like a virtual LAN link that lets two applications talk to each other on the same computer. It’s super crucial because it helps create virtual ports for testing and simulation.

With it, your emulator software can talk to the virtual devices it makes, causing errors and problems with the simulation. So, it’s essential to install this card to make sure it runs smoothly on the PC.

How to Use Loopback Adapter in Windows Operating System

If you’re using a Windows PC and want to connect the simulator software to an interface, you can follow these steps to set it up.

  1. If you haven’t installed the Cisco simulator on Windows, Linux, or macOS before, check out video training 1, video 2, and video 3 for help.
  2. Once you’ve installed GNS3 software, the first step is to add a Cisco Router and Switch IOS image. Watch this video to learn how to set up a Cisco Router image file.
  3. Once you’ve added the Router to the emulator, you can connect it to the physical LAN using the Loopback card. This lets you smoothly send data packets between the simulated LAN and the actual physical network.
  4. To open the Run window on your version 11 or 10 OS, press the Windows Key + R together on your keyboard. When the Run window pops up, type in hdwwiz and press Enter or click OK. This command will bring up the Hardware Wizard, which helps you add a new device to your computer or fix problems with an existing one.
  5. In the “Welcome to the Add Hardware Wizard” window, click “Next” to keep going.
  6. When you see the question “What do you want the wizard to do,” choose “Install the hardware that I manually selected from a list (Advanced)” and then click Next.
  7. In the “Common Hardware Types” window, find “Network Adapters” from the list of appliances and click Next.
  8. In the “Select the device driver you want to install for this hardware” window, after choosing “Microsoft” from the Manufacturer section, you’ll see a list of devices in the Model section.
  9. You can select “Microsoft KM-TEST Adapter” and then click on the “Next” button to proceed further.
  10. To start installing the virtual card in the “Hardware to install” window, just click the Next button. This kicks off the process of setting it up as needed.
  11. The installation of the network interface is about to start, and it should be finished quickly.
  12. Once you’ve added the Loopback interface, restart your computer.

How to Add IP Address to Loopback Interface

  1. In the Run window, type ncpa.cpl and press Enter or click OK. This directive will open the Network Connections window. From there, right-click on the Loopback Adapter and select “Properties.”
  2. In the “Properties” window, scroll down and select the “Internet Protocol Version 4 that is TCP/IPv4” choice. And here, select the “Use the following IP address” option.
  3. In the “IP address” area, type the IP address you want to add to the loopback interface. For example, you can use the IP address Also, in the “Subnet mask” field, enter the subnet mask for your network. For example, you can use

That’s it! You have now successfully added an IP address to your Loopback Adapter.

This process is like assigning an IP address to an interface on a Cisco Router, but it’s actually different.


Adding a Loopback adapter to your computer is essential for setting up GNS3 correctly. By following the easy steps in this guide, you’ll install the card smoothly and have your emulator program working well.

With this adapter, you can connect your simulated network to the real one and easily send data between them. Whether you’re an engineer or an IT pro, this guide is super helpful for getting the most out of emulators on your Windows PCs.

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