Exposing WSL's SSH to Windows

WSL (Windows Subsystem for Linux) has been an instrumental tool for developers who wish to leverage both Windows and Linux environments on a single machine. One commonly sought feature is the ability to SSH directly into the WSL environment from another device or even from the Windows host itself. This article will guide you through the steps to make this happen.

1. Setting up SSH in WSL

1.1 Installing the openssh-server

If you've previously installed the openssh-server, remove it first:

sudo apt remove openssh-server
sudo apt-get remove openssh-server

Then, install it:

sudo apt install openssh-server

1.2 Adjusting SSH Configuration

Open the SSH configuration file:

sudo vim /etc/ssh/sshd_config

Make the following changes:

• Set the listening port, for example, to 2222.
• Allow all addresses with ListenAddress 0.0.0.0.
• Allow password authentication by setting PasswordAuthentication yes.
• Permit root login by setting PermitRootLogin yes.

Once you've made the changes, restart the SSH service:

service ssh restart

2. SSH Connection from Windows

2.1 Testing Local Connection

Test the SSH connection from your Windows terminal:

ssh your-username@localhost -p 2222

2.2 Setting Up Port Forwarding and Firewall Rules

To expose the SSH server in WSL to external machines, set up port forwarding from Windows to WSL.

First, find your WSL's IP address:

ifconfig

Then, configure port forwarding:

netsh interface portproxy add v4tov4 listenaddress=0.0.0.0 listenport=2222 connectaddress=YOUR_WSL_IP connectport=2222

Next, add a firewall rule to allow incoming SSH connections:

netsh advfirewall firewall add rule name=WSL2 dir=in action=allow protocol=TCP localport=2222

You can also set this through the Control Panel's firewall settings.

To connect, use:

ssh name@your-windows-ip -p 2222

3. Handling Common Errors

If you encounter the following error:

ssh_exchange_identification: read: Connection reset by peer

Check if the port number in sshd_config matches the port you're forwarding in Windows. Adjust as necessary and retry.

4. Additional Port Forwarding

To add more port forwarding rules:

netsh interface portproxy add v4tov4 listenaddress=* listenport=80 connectaddress=YOUR_WSL_IP connectport=80  protocol=tcp

To remove or check rules:

netsh interface portproxy delete v4tov4 listenport=80 protocol=tcp
netsh interface portproxy show v4tov4

To change the WSL IP address:

netsh interface ip add address "vEthernet (WSL)" YOUR_NEW_IP 255.255.0.0

This article was inspired by the original post on CSDN by jasneik. The original post can be found here.