ssh tunneling on windows

Homepage | Contacts

• Introduction
• Creating a tunnel
• Connecting to the front-end host
• VNC client over ssh on windows

Introduction

To open an ssh tunnel from a windows machine to the front-end nodes via the BNL QCDOC ssh gateways (ssh.qcdoc.bnl.gov) you need to create an outgoing and an incoming tunnel. These instructions describe how to do this using a winSSH client.

Creating a tunnel

From your main ssh window click Quick Connect:

  Enter the Host Name and User Name in the pop-up window (the Port Number should be 22). The Host Name is the gateway machine. If you connecting to BNL use ssh.qcdoc.bnl.gov. For JLab use login.jlab.org. Then click Connect.

You will be prompted for password and once you get connected you will be asked (on another pop-up) to enter a profile name, kind of a shortcut for the connection. Choose a profile name, like bnl-tunnel or jlab-tunnel and click OK.

Having logged into the gateway host go back to the main ssh window, click Profiles and Edit Profiles ... on the pull down menu:

On the pop-up window, first check "Request tunnels only (disable terminal)" and click on Tunneling. Click the Add.. button to add an outgoing tunnel:

or, for JLab:

The Display Name could be anything of your choice. The Destination Host is the front-end node. The Listen Port is a port greater than 1024. You must use the same Port for both the Outgoing and the Incoming tunnels. Click OK when done to create the outgoing tunnel.

You then need to create an Incoming tunnel. Click on Incoming and then Add... to add an incoming tunnel:

or for JLab:

The Display Name is a name of your choice. Listen Port must be the same Port you used on the Outgoing tunnel. The Destination Host is the gateway host. Click OK when done to create the incoming tunnel.

Click OK at the bottom right of the profiles window to save the changes.

Having saved the changes, close the existing connection and restart by selecting the appropriate connection from the Profiles (this is what we called earlier bnl-tunnel or jlab-tunnel). You will be prompted for your password on the gateway host. You now have a tunnel to the front-end host.

Connecting to the front-end host

Having configured an ssh tunnel profile, you first need to start the tunnel. From the Profiles window, select the bnl-tunnel or jlab-tunnel profile. You will be prompted for your password on the ssh gateway. This will open the tunnel via the ssh gateway to the front-end host.

Having the tunnel started, you can now connect to the front-end node directly. Click on Quick Connect on the main ssh secure shell window. The Host Name on the pop-up will now be localhost and the port number will be 1234 or 2345 (as was set in the tunnel configuration).

When you click Connect you will be prompted for your password on the front-end node and will be connected.

NOTE 1: You may enter a profile name for the connection to the front-end host.

NOTE 2: If you close the tunnel connection, you will also loose the connection to the front-end host.

NOTE 3: You can open as many connections to the front-end host as you wish by simply clicking

on the "New Terminal Window" on the top of the front-end ssh window. You won't even be prompted

for password.

NOTE 4: You can transfer files directly from your window machine to the front-end host (drag and

drop) by clicking on the "New File Transfer Window" on the top of the front-end ssh window.

VNC client over ssh on Windows

• Download and install on your windows machine a VNC client (VNC Viewer) from RealVNC: http://www.realvnc.com/
• Start the VNC server on the front-end node:

qcdochostb:>vncserver :7 -fp /usr/lib/X11/fonts

New 'X' desktop is qcdochostb:7



Starting applications specified in /home/user/.vnc/xstartup

Log file is /home/user/.vnc/qcdochostb:7.log

• Create and start an ssh tunnel as described above. The Host Names on the Incoming and Outgoing tunnel are the same as above. The Port Number, however, should be 590X, where X is port that is used by the vnc server (7 in the above example). For example, this is what the outgoing tunnel should look like:

• Start the VNC client on the windows machine. The Server should be localhost followed by colon(:) and the port number:

     After clicking OK, you will be prompted for your VNC password that you   entered on the front-end host when you started the VNC server for the first time.

• A VNC session will start.

Homepage | Contacts

Last Modified: February 1, 2008

One of ten national laboratories overseen and primarily funded by the Office of Science of the U.S. Department of Energy (DOE), Brookhaven National Laboratory conducts research in the physical, biomedical, and environmental sciences, as well as in energy technologies and national security. Brookhaven Lab also builds and operates major scientific facilities available to university, industry and government researchers. Brookhaven is operated and managed for DOE’s Office of Science by Brookhaven Science Associates, a limited-liability company founded by Stony Brook University, the largest academic user of Laboratory facilities, and Battelle, a nonprofit, applied science and technology organization.

Privacy and Security Notice  | Contact Web Services for help