X11 is a communication protocol for "forwarding" graphics from one machine to another. In order to display graphics or run programs interactively with PuTTY, VcXsrv must be running as well. To start using VcXsrv

1. Download and install VcXsrv
2. From the start menu, search for XLaunch
   
3. Select the configuration options that you would like, here we use "Multiple windows", "Start no client", and the default "Extra settings" parameters
   
4. After clicking finish, you will see the XLaunch logo in the Task bar (note that you may have to expand it)
   
   
5. Now, you are all set for PuTTY with X11 fowarding

PuTTY is an SSH and telnet client, developed originally by Simon Tatham for the Windows platform. PuTTY is open source software that is available with source code and is developed and supported by a group of volunteers. It can be downloaded here and is commonly used alongside VcXsrv for X11 Forwarding.

1. Download and install PuTTY (https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html)
2. Make sure you have XLaunch running (see above)
3. Find PuTTY in the start menu, and start the application
   
4. For host name, you make connect to a number of resources (e.g., head.arcc.albany, headnode7.arcc.albany.edu, lmm.its.albany.edu), here we will connect to the headnode head.arcc.albany.edu
   1. Enter head.arcc.albany.edu and port 22 as shown below
      
   2. Next click on Connection -> Data and enter your netid in the "Auto-login username" field
      
   3. Next click on Connection -> SSH -> X11  on the left side, and check "Enable X11 forwarding", this will allow graphics to forward to your screen
      
   4. Finally, go back to "Session" and enter a session name and hit "Save". This will store these properties so that you can use them again by selecting the session and clicking "Load".
      
5. Finally, click open on the bottom right and click Yes when prompted by the PuTTY Security Alert
   
6. Enter your password when prompted. You will not see your password appear on the screen, but it is being typed!
   
7. When successfully connected, you will see a terminal display something that looks similar to
   
8. Now you are all set! To test if X Forwarding is working correctly,enter in the command line: xeyes and you should see the following window pop up
   
9. If you are having trouble, please contact askIT@albany.edu

On windows 10, you can run Ubuntu natively. Follow the tutorial from Microsoft here: https://docs.microsoft.com/en-us/windows/wsl/install-win10

SSH to head.arcc.albany.edu

Just as you would on a regular linux terminal, you can SSH directly to head.arcc.albany.edu

X11 is a communication protocol for "forwarding" graphics from one machine to another. In order to display graphics or run programs interactively with the Terminal, XQuartz must be installed. To download and install XQuartz, please click here

To SSH to any of our resources (e.g., head.arcc.albany, headnode7.arcc.albany.edu, lmm.rit.albany.edu), you can use the terminal in Mac. Here, we will connect to head.arcc.albany.edu.

1. Install XQuartz if you have not yet done so.
2. Right click on XQuartz in the toolbar.  Select Applications → Terminal
3. Enter into the terminal: ssh -Y [netid]@head.arcc.albany.edu  
   1. NOTE: the -Y option is required in order for your X11 applications to work
4. Enter your password when prompted. You will not see your password appear on the screen, but it is being typed!
5. Type y when prompted by the security alert (you may not see this alert)
6. After you are successfully logged into the ssh session, you will need to enter the following command:  touch .Xauthority
   1. NOTES:
      1. you only need to do this if the file does not already exist. 
      2. there is a "." at the beginning of the filename ".Xauthority"
7. Now you are all set! To test if X Forwarding is working correctly, enter in the command line: xeyes
   1. you should see a window with eyes pop up
8. If you are having trouble, please contact askIT@albany.edu