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Fix port conflicts and network issues preventing access to the VNC desktop.

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Port 6080 already in use

Symptoms:
  • VNC web page won’t load
  • “Port already allocated” error
Windows (PowerShell):
netstat -ano | findstr :6080
# Note the PID (last column)
taskkill /PID <PID> /F
macOS/Linux:
lsof -i :6080
kill <PID>
Edit .devcontainer/devcontainer.json:
"forwardPorts": [6081, 5901],
"portsAttributes": {
  "6081": {
    "label": "Desktop (noVNC)",
    "onAutoForward": "openBrowser"
  },
  "5901": {
    "label": "Desktop (VNC)",
    "onAutoForward": "ignore"
  }
}
Then access: http://localhost:6081After making this change, rebuild the container:
  • Press F1 → “Dev Containers: Rebuild Container”
1

Open Ports view

View → Ports
2

Add port forward

  • Click “Forward a Port”
  • Enter 6080
3

Access VNC

Open http://localhost:6080 in your browser

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Cannot access VNC

Symptoms:
1

Open Ports tab

View → Ports
2

Verify port 6080

Port 6080 should be listed and forwarded. If not, add it manually.
Inside the container terminal:
# Check if VNC processes are running
ps aux | grep vnc
sudo supervisorctl status desktop-lite

# Restart if needed
sudo supervisorctl restart desktop-lite
Wait 30 seconds after restarting before accessing VNC.
If browser-based VNC isn’t working, use a VNC client:
  • Download a VNC client (TigerVNC, RealVNC, etc.)
  • Connect to: localhost:5901
  • Password: ros
This bypasses the noVNC web interface.

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Port forwarding not working on remote SSH

If you’re running VS Code connected to a remote machine via SSH:
  1. Ensure port forwarding is enabled in your SSH configuration
  2. Check that firewalls aren’t blocking the forwarded ports
  3. Try accessing via the remote machine’s IP: http://<remote-ip>:6080
  4. Configure VS Code’s remote port forwarding explicitly in settings

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