Using tsvnc to connect to the CSS linux lab

While it is possible to use an X11 client such as Xming or to connect to the linux lab, unless you're on the campus network, you will almost certainly notice an unacceptable amount of lag and delay. This document will show you how to connect using ssvnc, a utility to automate the steps required to create a secure and fast 1) graphical connection. It's possible to do all this manually, but the ssvnc bundle makes it a lot easier.

Mac users, pay particular attention to the “SSH Local Protections” setting. If you miss this step, tsvnc will not work.

Mac OS X Lion users (and other users of the 64-bit Mac kernel), you may have use “export UNAME=Darwin.i386” before executing tsvnc in the Terminal (or you can cheat and rename Darwin.i386 to Darwin.x86_64). Otherwise tsvnc will complain about not finding the folder Darwin.x86_64, and using build.unix like it asks may result in tsvnc complaining about not finding vncviewer and then failing when you try to connect to the lab.

  1. Go to and download the latest version of ssvnc. The “Download Now!” link will probably be the most appropriate for your system, but if you want to install it on a few different machines and they aren't all the same type, download the “ssvnc_all” zip file, which contains everything you need to run it under Windows, OS X and linux.
  2. Extract the files from the zip file. Under Windows, you can do this by right-clicking on the zip file and choosing “extract all”. Under OS X, you can double-click on the zip file. Under linux, you can use the command unzip from the command line.
  3. Open the folder for the appropriate operating system and launch the “tsvnc” script. If you're using a graphical environment, double-clicking on the tsvnc or tsvnc.bat file should do it. From a linux command line, /path/to/tsvnc should work, if you use the actual path, not ”/path/to”.
  4. In the dialog you just launched, there is a space for “VNC Terminal Server”. Enter your UW NetID, then the ”@” symbol, then the name of the css linux lab host you wish to log in to. For example, my UW NetID is “jdlarios” and I want to log in to I would enter Once you've done that, click on “Options”.
  5. In the Options menu, check “Desktop Type”
  6. In the Desktop Type menu, choose “xfce” if you are connecting to uw1-320-00 through uw1-320-15 or “gnome” if you are connecting to uw1-320-16 through uw1-320-22 – I highly recommend 00 through 15 – then click “Done”. Do not choose “gnome” as the Desktop Type if you are connecting to uW1-320-00 through uw1-320-15; it will create a session with no menu and no easy way to exit and start over.
  7. Back in the Options menu, click on “Advanced”.
  8. In the Advanced menu, make sure that “SSH Local Protections” is not checked. Leaving this checked protects you against other users of the machine from which you are connecting, but if you are connecting from your own personal machine, that shouldn't be a problem. Leaving the box checked will make the process fail if you're using recent versions of OS X. I don't think this option is available in Windows, and I don't know about Linux, but if you see this option I figure it's best to just disable it. Once you've done that, click “Done”.
  9. (Optional) Click on “Save” to save this configuration to a file in your documents folder somewhere. Next time you run tsvnc, you can load the configuration file and skip all of the steps above.
  10. Click on “Connect”. This will launch a new window which, depending on if you've connected before, may ask you to verify that you want to continue. If it does this, type “yes” and press enter. Next, it will ask for your password. Enter your UW NetID's password and press enter.

If all has gone well, you should now be connected to one of the linux lab machines, with a graphical environment. Depending on your network speed, it may be a little sluggish, but nowhere near as slow as some other methods of getting to the graphical desktop are.

If you lose the connection or close the VNC window, your session with the linux machine will persist. Just re-launch the connection using the steps above (obviously you won't need to download or extract the ssvnc package again; just start with step 3) and make sure you connect to the same machine, and your session should be restored.

DO NOT USE the alias for connecting this way. That will connect you to a machine at random, and you will not be able to re-connect to that session later, unless you happen to randomly get the same machine again. Use a named node between and

There are plenty of other options available; feel free to experiment with them, keeping in mind that some may cause the connection to fail. Others may speed it up at the expense of stability. I haven't played with all of the options yet, so I don't know how all of them work. The options detailed here are the ones I know should get you a connection.

Important bug workaround

If your password contains a space character, there is one further step you need to take the first time you log in:

  1. Open the Keyboard Preferences panel from the System menu → Preferences → Keyboard:
  2. Click on the Layouts tab, then next to “Keyboard model”, click Choose:
  3. Select the “Dell 101-key PC” and click ok:
  4. Close the preferences panel.

This works around a bug where, if the screensaver kicks in and prompts you to enter your password to unlock the screen, the password dialog doesn't accept the space character. It may be a good idea to take these steps even if you don't use the space character in your password – I don't know for sure that the screensaver password dialog is the only place affected by this bug.

1) Fast compared to straight X11, that is. It will still be slow if you're on dialup, and it's not as fast as sitting at the console. This won't be suitable for playing video games, in other words, but it should work for most other tasks.

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