WSL Networking and Port Forwarding
Considering vLLM is running inside WSL, and we are trying to expose it to the Windows network.
Step 1: Confirm WSL Server Is Listening on 0.0.0.0
In your docker-compose or command, make sure vLLM is not bound to 127.0.0.1. It should be bound to all interfaces (0.0.0.0):
python3 -m vllm.entrypoints.openai.api_server --host 0.0.0.0 --port 8000
Also, confirm with:
netstat -tuln | grep 8000
Should show:
tcp 0 0 0.0.0.0:8000 0.0.0.0:* LISTEN
Step 2: Identify the WSL IP
Inside WSL, run:
ip addr | grep inet
You’ll see something like inet 172.22.x.x — that's the internal IP of your WSL instance. But this is not accessible from the outside.
Step 3: Set up Port Forwarding (From Windows Host to WSL2)
Since WSL2 is on a different virtual network, you need to forward ports from the Windows host to WSL.
Use PowerShell as Administrator on Windows and run:
netsh interface portproxy add v4tov4 listenaddress=0.0.0.0 listenport=8000 connectaddress=WSL-IP connectport=8000
Replace WSL-IP with the IP from Step 2. You can also use localhost if you're sure the service is bound to 0.0.0.0 in WSL.
Example:
netsh interface portproxy add v4tov4 listenaddress=0.0.0.0 listenport=8000 connectaddress=172.22.64.1 connectport=8000
Then enable the firewall rule:
netsh advfirewall firewall add rule name="vLLM Port 8000" dir=in action=allow protocol=TCP localport=8000
Step 4: Use Your Windows Machine’s Private IP
From another machine on your LAN, access your vLLM server using:
http://<your-windows-private-ip>:8000
You can find this by running on Windows CMD:
ipconfig
Look for the IPv4 Address under your active network adapter (e.g., 192.168.x.x).
Step 5: Verify from Another Device
Try this in your browser or with curl:
curl http://<windows-ip>:8000/v1/models
You should get a response from the vLLM server.
(Optional) Clean Up Forwarding Rules
To remove the proxy:
netsh interface portproxy delete v4tov4 listenport=8000 listenaddress=0.0.0.0
⚠️ Notes
If you're using Docker inside WSL2, ensure Docker is binding to 0.0.0.0, or use Docker’s ports section in docker-compose.
Windows Defender Firewall can block incoming traffic. Ensure the port is allowed
WSL2 still doesn’t support host bridging, so this proxying is a stable workaround.
