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Graphical logon to Stallo.
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1 Introduction
The VNC protocol is a better protocol to run graphics output from Stallo than using the native X11 protocol as it is less latency sensitive thus greatly improving the interactive response over long distances and slow networks. It is also simpler to set up on clients running Windows.
2 Basic description
As the VNC protocol is unsafe (or rather, unencrypted) it is blocked by the firewall running on stallo. Therefore you need to sneak through the firewall using something called ssh tunnelling. This is a way to run unencrypted network protocols within the safety of an encrypted ssh connection. To make things overly short: You will trick the client software running on your desktop into believing that you are connecting to the local machine (your desktop) and ssh will forward your connection to the remote machine (Stallo) seamlessly.
3 Windows setup
3.1 Requirements
- A login account on stallo.uit.no.
- An ssh client if you are connection from outside the UiT network [1], we will use Putty in this example.
- A VNC client, we will use RealVNC, an alternative is TightVNC.
We assume that you know how to download and install the above software under windows, do it now. You can find a screencast of how to do the setup below here. The video is in the Theora format which is an open standard for video content, you might need to download these codecs to make it work in Windows Mediaplayer.
3.2 Creating the tunnel.
(If you are on the UiT network [1] skip to Starting VNC.)
Start Putty by clicking on the icon that you most probably have on your desktop now, if not look in the Start menu. You should then get a window with fields to fill in the host to connect to. Fill in stallo-wgw.uit.no as the address to connect to. stallo-wgw is the machine where we have installed the vnc server software. It should then look something like this
Click on the SSH entry in the left column, click on Tunnels and then fill in the tunneling info
Source Port should be 5950 and Destination should be localhost:5950, then click on the Add button. The window should now look something like this:
Now you go back to the Session entry and connect to stallo-wgw.uit.no, you should now get a terminal window where you can log in with your username and password. Once you have logged in you also have established a secure tunnel that is forwarding port 5950 from your desktop to stallo-wgw. (You do not need to do anything more in the terminal window you get when logging in through putty, but do not close the window as it will terminate the ssh-tunnel and you will loose your connection to stallo-wgw.) It is also recommended that you save your putty-setup for this tunneling so you do not have to type in all the magic every time you want to use this service. Maybe stallo-vnc-tunnel is a good name for it?
3.3 Starting VNC
Start the vnc-client by clicking on the icon. You should now have a window like this
If you are on local network [1] you can fill inn stallo-wgw.uit.no:5950. If you are connecting from an external network and have set up the ssh tunnel as described above fill in localhost:5950 as the server to connect to. Click OK and you will get a graphical login screen like this
fill in you username and password again and you should now have a graphical desktop looking something like this
your right mouse button will give you menu where you can open more windows. You can now run graphical applications within this session like this
Yes, we know. This is a really simple stripped down desktop, it's actually how the desktops in UNIX used to look like in the early nineties... The purpose of this service is not to provide a full terminal service environment, but only to provide a possibility to run simple graphical applications from the Stallo system without the need to install a full X-server setup on your desktop. The vnc protocol can also adjust to network bandwidth and latency so running this over long distances gives a better interactive response than using the native X11-protocol directly.
4 Linux setup
- Connect to stallo-wgw.uit.no with tunneling of port 5950 to the remote host:
ssh -L5950:localhost:5950 stallo-wgw.uit.no
- Start the vnc client, for instance the vncviewer:
vncviewer localhost:5950
That's it, you should now have a the same login screen as above. (And they say Windows is easier to use than Linux...)
5 Feedback
This is an experimental service so feel free to give comments either on this page (you need to login) or to support-uit@notur.no.
| [1] | (1, 2, 3) Outside the UiT network means outside the uit.no domain or to be accurate outside the 129.242.0.0/16 domain. If you are unsure if you are outside our network or not you can check your address using WhatIsMyIP. If your ip starts with 129.242 you are on the inside. If you are on the outside and have a UiT user id you can use VPN to get in. Once you have logged into the VPN service you will see that your IP has changed on WhatIsMyIP. |
