SSH Tunnel Howto

This page is intended to show you how to access Green Banks internal web pages. A Green Bank unix account is a pre-requisite for this to work. If you do not have an account this method will simply not work. Please do not email us asking for an account. Unless you are a member of staff or a legitimate observer we cannot give you one.

Naturally the methods for establishing an ssh tunnel differ according to your operating system.

Linux

This method should work for any unix system, not just linux, assuming you have the ssh clients installed

First, create a tunnel from port 8080 on your local machine to port 3128 on the Green Bank proxyserver:

ssh -N -L 8080:proxy.gb.nrao.edu:3128 login.gb.nrao.edu &

You will be prompted for your unix username and password.

Windows

There are many ssh clients out there and methods for setting up tunnels. The following instructions are for putty which is available free from http://www.chiark.greenend.org.uk/~sgtatham/putty/

When you fire up putty you will see in the category pane (towards the bottom) "Tunnels" Clicking on that will bring up the tunnels configuration. The top section deals with X11 forwarding, set this as you will, bearing in mind that if you are a long way off in network terms the performance will be abysmal. The lower section is hwere we set up the tunnel. Under "Add new forwarded port" enter 8080 in the "Source port" box and in the "Destination" enter proxy.gb.nrao.edu as shown below and then click on add.

Now click on "Session" in the category pane and enter "login.gb.nrao.edu" in the "Host Name (or IP address)" box, select the SSH protcol button and finally click on "Open"

Now the tunnel is in place you need to configure your browser to use the proxy. If your browser supports proxy autoconfiguration scripts then point it to http://www.nrao.edu/poorvpn.pac This script only uses the proxy for web addresses ending in .nrao.edu all others are fetched directly as before.

For Netscape and Mozilla, edit your preferences, choose "Advanced", then "Proxies", and select the setting "Automatic proxy configuration URL:". For IE, it's under Tools -> Internet Options -> Connections -> Local Area Network Settings.

For more information and other tricks you can pull using ssh tunnels have a look at the THE GOLD BOOK VPN page.

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The National Radio Astronomy Observatory is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.