Shell Script to Tunnel VNC Sessions over SSH (Improved)

Following is a parameterized shell script which you can use with this syntax:

Usage: vnctunnel [ssh session] [screen] [vnc options]
Example: vnctunnel user@server :1

It's "improved" because it's completely parameterized--you can specify the SSH session, screen, and even vnc options.

(Assuming you copy it to your ~/bin directory and make it executable)

#!/bin/sh
# This is a parameterized script to SSH tunnel a VNC session
# Ryan Helinski

# Local settings
# Change this if you don't like `vncviewer'
VNCVIEWER=vncviewer
# Change this if you use ports near 25900 for something else locally
PORTOFFSET=20000
# Apply extra options to vncviewer
VNCOPTS="--AutoSelect=0 $3"

if [ $# -lt 2 ] ; then
        echo "Usage: $0 [ssh session] [screen]";
        echo "Example: $0 user@server :1";
fi

SSHPARM=$1;
SCREEN=`echo $2 | cut -d':' -f2`;
SSHPORT=$[$SCREEN+5900];

echo "Session: $SSHPARM, Screen: $SCREEN, Port: $SSHPORT"

ssh -f -L $[$PORTOFFSET+$SSHPORT]:localhost:$SSHPORT $SSHPARM sleep 10; \
        vncviewer localhost:$[$PORTOFFSET+$SSHPORT]:$SCREEN $VNCOPTS

exit

Shell Script for Tunneling VNC over SSH

If you use VNC over the Internet rather than just over your LAN, it is not recommended to allow the 2590x port to be forwarded to the Internet. Instead, if you already have port 22 for SSH forwarded to the machine you want to get VNC from, you're all set to connect securely via an SSH tunnel. Note that you still have to have VNC set up and working on the LAN and know which screen number you are using (if you've used the GUI to allow your desktop to be connected to remotely, then you are using screen 1). This can also be accomplished using PuTTy with its GUI.

Replace {user} with your username on the remote machine, and the {WAN Address} with your public IP address on the remote machine. Replace the screen with the (single) number of the screen you use (1,2,3,...). Due to technical limitations, I can't use backslashes, so please make the command a one-liner. The ssh with the sleep argument needs to have a command after it that uses the forwarded port or it will close immediately.

#!/bin/sh

ssh -f -L 2590{screen}:127.0.0.1:590{screen} 
 {user}@{WAN Address} sleep 10; 
 vncviewer 127.0.0.1:2590{screen}:{screen};

exit

So an example script would look like:

#!/bin/sh

ssh -f -L 25901:127.0.0.1:5901 user@mysubnet.domain.com sleep 10; 
 vncviewer 127.0.0.1:25901:1;

exit