Using a Mirrored Network with WSL2 for Docker Desktop: A NAT Perspective

Introduction

The Windows Subsystem for Linux (WSL) is a compatibility layer for running Linux binary executables natively on Windows 10 and Windows Server 2019. WSL2, the second version of WSL, uses a real Linux kernel to provide better performance and full system call compatibility. With WSL2, you can run a Linux distribution alongside your Windows operating system, providing a seamless experience for development and testing.

Mirrored Network with WSL2

A mirrored network in WSL2 can be used to provide network connectivity between the host Windows operating system and the WSL2 distribution. This can be especially useful when working with containers, as it allows for seamless communication between the host and the containers running inside the WSL2 distribution. By default, WSL2 uses NAT for network connectivity, but a mirrored network can be used instead to provide a more direct connection.

Setting up a Mirrored Network with WSL2

To set up a mirrored network with WSL2, you will need to make some changes to the network settings for your WSL2 distribution. Here are the steps to follow:

1. Open the Windows Terminal and start your WSL2 distribution.
2. Check the current network configuration by running the following command:

This will display the current IP address and network configuration for your WSL2 distribution.

3. Stop the WSL2 distribution by running the following command:

This will stop the WSL2 distribution and allow you to make changes to the network configuration.

4. Open the Windows Registry Editor and navigate to the following key:

This key contains the network configuration settings for WSL2.

5. Create a new DWORD value with the name NetworkingMode and set the value to 0.
6. Create a new DWORD value with the name HostNetworkingMode and set the value to 1.
7. Restart your WSL2 distribution by running the following command:

This will start the WSL2 distribution with the new network configuration settings.

Testing the Mirrored Network with Docker Desktop

To test the mirrored network with Docker Desktop, you can run a container and check the network connectivity. Here are the steps to follow:

1. Install Docker Desktop on your Windows operating system.
2. Start the Docker Desktop application.
3. Open the Windows Terminal and start your WSL2 distribution.
4. Run the following command to start a container:

This will start a container running the Alpine Linux distribution and ping the Windows host operating system. If the ping is successful, it indicates that the mirrored network is working correctly.

Using a mirrored network with the default WSL2 distribution and NAT can provide a more direct network connection between the host Windows operating system and the WSL2 distribution. This can be especially useful when working with containers, as it allows for seamless communication between the host and the containers running inside the WSL2 distribution. By following the steps outlined in this guide, you can set up a mirrored network with WSL2 and test the network connectivity with Docker Desktop.

• WSL2 is a compatibility layer for running Linux binary executables natively on Windows 10 and Windows Server 2019.
• A mirrored network in WSL2 can be used to provide network connectivity between the host Windows operating system and the WSL2 distribution.
• To set up a mirrored network with WSL2, you will need to make changes to the network settings for your WSL2 distribution.
• Testing the mirrored network with Docker Desktop can be done by starting a container and checking the network connectivity.

References

• Microsoft. (2021). Windows Subsystem for Linux. https://docs.microsoft.com/en-us/windows/wsl/about
• Docker. (2021). Docker Desktop for Windows. https://www.docker.com/products/docker-desktop