Serendip is an independent site partnering with faculty at multiple colleges and universities around the world. Happy exploring!

You are here

Remote Desktop

Kathy Maffei's picture
On Doug's advice, I've used vnc in past courses to get a remote desktop to work from home on my Windows machine. I'd had problems with changes in security, but last night I got it running just fine. Of course, there's a bit of delay, but it's quite nice. Lucid Life is almost as impressive as in class, and python CAs pop up nicely. I'm using a cable internet connection at home, so I'm not sure what a dial-up would look like... In case someone else would like to try it, I figured to document it here. I’ll describe it in detail for anyone not already familiar with these programs. I'm using PuTTy (a free, non-installed executable) to create a secure shell to one of the lab computers. The shell needs to create a tunnel through which the vnc client will connect, since BMC security blocks vncserver requests otherwise. So, in your PuTTy settings under Connection -> SSH -> Tunnels, you need to create a Forwarded Port: 1) Type in any 4-digit # you like for Source Port (and remember it) 2) Under Destination, type in the machine name you're connecting to, a colon, and 5901 ( for example) 3) Click Add Under Session, the Host Name should be the name of the computer you’re connecting to (same as Destination in your Forwarded Port setting - for example) and Protocol should be SSH. You can save your settings by typing in a name under Saved Sessions and clicking Save. Click Open to open the connection. Once you've given your name & password to log onto the lab computer through PuTTy, type "vncserver" at the prompt. The first time you do so, you'll be asked to create a password for your vncserver sessions - you'll need this password every time you run vnc viewer. You'll also be informed that a desktop was created for you on the machine. Here's an example of what it says: New ' (kmaffei)' desktop is Notice that I was given desktop 1. If I had logged in after someone else had already done so and created themselves a vnc desktop, I would have been given desktop 2 ( – or 3 or 4, etc. Here's the weird part. Although I've never had to test this theory, I'm told that if I am going to end up with desktop 2, then the Forwarded Port I created in the tunnels section of PuTTy should have been ( Of course, this requires some form of prescience, so I start with 1. I guess if I ended up with 2, I’d try connecting with vnc, anyway, to test the theory. If it didn’t work, I’d have to kill my vnc desktop from PuTTy (type “vncserver -kill :#” – where # is whatever number desktop I was just given), log off the lab computer in PuTTy (type “exit” at the prompt), and reconfigure the Forwarded Port for whatever desktop I figured I’d end up with when I logged back on. Hopefully, I’d do this quick enough that when I logged back onto that computer, I was given the desktop # I expected! I hope we don’t run into this issue, but if enough of us use vnc to log on remotely, then it might happen. Perhaps we can coordinate and each select a different lab computer to log into. FYI, I’ve been using trs80. OK, once you’ve successfully created your vnc desktop with PuTTy, you’ll run VNC Viewer (just like PuTTy, a free executable). You only need the viewer. Open your vncviewer and type into the Server box “localhost::####” where #### is the 4 digit number you chose as a Source Port when you set up the Forwarded Port in PuTTy. Notice the two colons between localhost and the port number. Click OK and you’ll be prompted for a password – this is the one you gave the 1st time you ran vncserver from the PuTTy window. Then your desktop will pop up. There are some quirks to get used to – you have no right-click, and windows are slightly different. When a new window pops up, it’s only an outline you drag with your mouse until you decide where to place it and click on the screen to drop it. Also, I have yet to figure out how to close a window in this new vnc version, so when the python CA pops up the drawing window, I must Ctrl-C in my terminal window to get control back (as someone discovered in class yesterday). There are also some settings under Options in vncviewer before you connect – color and inputs. Cleaning up: once you’re done and you’ve closed your vncviewer, you’ll need to kill the desktop in the PuTTy terminal window by typing “vncserver -kill :#” – where # is whatever number desktop you were using. The reply should be something like: Killing Xvnc process ID 11218 Good luck and please let me know if you discover anything different or additional to what I've written. Doug may have some to add - I think he uses this.