VNC: Tunneling with PuTTY

Do you want to know how you can remotely access a computer in a LAN from outside with VNC?

Well, theoretically it is impossible to access any computer in a LAN from outside. Not if you know how to do port-forwarding! Tunnels? Yeah. We're going to create tunnels.

OK. Let me share with you how to use PuTTY to do port forwarding. What you need is:

1. a gateway (a computer with interface to both LAN and WAN) running SSH daemon.
2. another computer running VNCserver in the LAN.
3. a computer to connect from outside, having both PuTTY and VNCviewer.

Let us continue with the steps, with PuTTY first:

1. Run PuTTY.
2. In PuTTY, choose from Category menu, choose Connection-->SSH-->Tunnels
3. Tick both options:
• Local ports accept connections from other hosts
• Remote ports do the same (SSH-2 only)
4. Put Source port: 5901
5. Put Destination: <LAN IP>:5901
6. Click "Add" button.
7. Choose Session
8. Put gateway IP, port 22
9. Click on "Open" button.
10. Login to SSH via PuTTY

Next is what we need to do with our VNCviewer. In this example I'm using RealVNC. You may get a copy for free and test it out. Let's continue:

1. Run VNC Viewer
2. In Server field, put localhost:1
3. Press "OK" button.
4. That's all! Believe me, it's working already.