Run SSH on WSL

SSH can be used to connect to WSL and to copy files from Windows.

If you only want to copy files between Windows and WSL on the current machine, SSH is not needed.

WSL automatically mounts the Windows C:\ drive on /mnt/c

For example, if you download a file while using a browser in the Windows Downloads directory and you want to bring it into Linux use the cp command.

Substitute your username and the filename to be copied.

    

        
        
            cp /mnt/c/Users/<username>/Downloads/<filename> .
        
    

If SSH is needed to access WSL from a different machine continue with the instructions below.

Install SSH server

Install the SSH server inside the Linux distribution.

    

        
        
            sudo apt install openssh-server -y
        
    

Start the SSH server:

    

        
        
            sudo /etc/init.d/ssh start
        
    

The SSH server can also be started automatically using systemd. Refer to the systemd information.

Once the SSH server is started, it’s possible to ssh from the Windows Command Prompt to WSL.

Make sure to add the Linux username to the ssh command if the Windows username is different from the Linux username.

    

        
        
            ssh.exe user@localhost
        
    

Change the SSH server port

You can use a higher port number for the SSH server. Do this if you are not able to connect from another machine.

Modify the SSH config file to change the port number for the SSH server.

Use port 2022 for SSH instead of the default port 22.

Use a text editor to modify the file /etc/ssh/sshd_config and uncomment the #Port 22 to be just Port 2022

To edit from the command line:

    

        
        
            sudo sed -i -E 's,^#?Port.*$,Port 2022,' /etc/ssh/sshd_config
        
    

Restart the SSH server for the new port to be used:

    

        
        
            sudo /etc/init.d/ssh stop
sudo /etc/init.d/ssh start
        
    

Use ssh with -p to specify the new port.

    

        
        
            ssh user@localhost -p 2022
        
    

There are two options to SSH from another machine on the local network:

• Bridged networking
• Port forwarding

Bridged networking

WSL uses NAT by default. This means the Linux distribution running in WSL will get an IP address starting with 172.X.X.X and not an IP address on the local network. NAT makes it impossible to SSH to WSL.

One way to get an IP on the local network is to use a bridged network.

For more information refer to the short WSL bridging and networking reference

Port forwarding

Another way to connect to WSL via SSH is to forward or proxy the Windows port for SSH, such as 2022, to the WSL instance.

Before starting, find the IP address of the WSL instance.

    

        
        
            wsl hostname -I
        
    

Save the IP address.

Run New-NetFirewallRule from a PowerShell prompt with Administrator privilege to allow port 2022 from outside Windows:

    

        
        
            New-NetFirewallRule -Name sshd -DisplayName 'OpenSSH Server (sshd) for WSL' -Enabled True -Direction Inbound -Protocol TCP -Action Allow -LocalPort 2022
        
    

Run netsh from a Windows Command Prompt with Administrator privilege. Substitute the IP address with the one found using the wsl hostname command above for the connectaddress. This forwards port 2022 to the WSL IP address.

    

        
        
            netsh interface portproxy add v4tov4 listenport=2022 listenaddress=0.0.0.0 connectport=2022 connectaddress=172.18.164.187
        
    

Try to ssh from another machine on the local network.

Get the IP address of Windows:

    

        
        
            ipconfig
        
    

From another local machine SSH to the Windows IP on port 2022 and it should forward to WSL running on that Windows computer.