Remote access to Linux - how to set up a VNC session from a remote PC

Overview 

VNC = Virtual Network Computing http://en.wikipedia.org/wiki/VNC enables you to set up a connection from a remote host (e.g. a PC offsite) to a session on a SLAC Linux host.  For access to control system components such as edm displays or matlab programs, VNC often provides the best performance.

This document contains instructions for setting up a connection from a Windows PC to a VNC linux session.  

Set up your PC (one time)

• Install vpn if you don't have it already. Instructions from SCCS are here: https://confluence.slac.stanford.edu/display/NetMan/How+to+Connect+to+SLAC+VPN
• Download and install the vnc for windows viewer client software executable from here: http://www.realvnc.com/products/free/4.1/winvncviewer.html; (make a shortcut on your desktop)
• Download and install putty, if you don't have it already. Once you install and run vpn, you can get putty from the SLAC xweb: https://xweb.slac.stanford.edu

Configure your vncserver (one time)

• vpn into the SLAC network, see https://confluence.slac.stanford.edu/display/NetMan/How+to+Connect+to+SLAC+VPN
• Using putty (or XWin-32 if you prefer) log into iris01.slac.stanford.edu, providing your unix username and password
• Create your vnc password:
  • > vncpasswd
    Provide a password following the usual SLAC password guidelines.
    The password will be stored in ~/.vnc/passwd
    To reset the password, run vncpasswd again.

• Protect the password:
  • > fs setacl ~/.vnc system:slac none
  • > fs setacl ~/.vnc system:authuser none

• Start vncserver to create your xstartup file:
  • > vncserver -localhost -nolisten tcp -geometry 1440x900
  • Make note of the display number that is returned, for example:
    jrock@iris01> vncserver -localhost -nolisten tcp -geometry 1440x900
    New 'iris01:3 (jrock)' desktop is iris01:3
    Starting applications specified in /u/cd/jrock/.vnc/xstartup
    Log file is /u/cd/jrock/.vnc/iris01:3.log
    In this case, 3 is the display number, which is a unique ID for your particular vncserver session.
    in the following instructions, the display number is indicated by displaynum

• Kill the server:
  vncserver -kill :displaynum
  for example
  vncserver -kill :3

• Edit your vnc xstartup file to invoke kde at startup:
  • > emacs ~/.vnc/xstartup
    change last line from "twm" & to "startkde&", save and close

Run your vnc server (as needed)

• > vncserver -localhost -nolisten tcp -geometry 1440x900
  (or use desired display parameters, see.....)
  Again, make note of the displaynum - you'll need to use it to connect from Windows.

The session will continue to run until you -kill it, or until SCCS does.

Connect from Windows (everytime you need to)

• Create a connection to SLAC using vpn (see vpn link above)
• Invoke a command window on your PC:
  • click the Start Button in the lower lefthand corner of your screen
  • enter Command in the search box
  • select "Command line tools" from the list
• In the command window, use putty to create a secure scp tunnel to the vncserver host, and your vncserver port:
  • putty -ssh -L pcport:localhost:59displaynum vncserverhost.slac.stanford.edu
    • pcport = port on your pc, 590anything, e.g. 5901
    • displaynum = 2-digit vncserver session i, as noted when you started the vncserver, with leading 0 if needed, see above
    • vncserverhost = host where vncserver is running
  • for example
    putty -ssh -L 5901:localhost:5903 iris01.slac.stanford.edu
    or
    putty -ssh -L 5902:localhost:5912 iris02.slac.stanford.edu

• Now run the vnc client:

References 

SLAC Linux VNC page: http://www.slac.stanford.edu/comp/unix/vnc.html

contacts:

• Judy Rock
• Jingchen Zhou