Ubuntu – How to use PuTTY to get X11 connections over ssh from Windows to Ubuntu

puttysshx-forwarding

I need to get remote X11 terminal access from Windows machines into my Ubuntu 16.04 system. I am choosing not to use RDP for this since this only affects the two Windows clients.

From the other Linux boxes it is simple, especially since they use RSA authentication:

pi@rover$ ssh -Y prime5

and wham, bam, I just get the prompt

pi@PRIME5:~$

But from Windows I use PuTTY which gives a great CLI connection. Quick and easy, and it saves creds so the connections are made very quickly.

When I type this on the Ubuntu command line

pi@PRIME5:~$ echo $TERM
norm

Which means that GUI applications will not run.

I see PuTTY has the X11 option.

But it throws an error instead of working.
It needs an X server on the client side to work with Putty.

Question is in the title: How to use PuTTY to get X11 connections over ssh from Windows to Ubuntu?

Best Answer

Michigan Tech has a very succinct explanation of how to use Xming here:

Installing/Configuring PuTTy and Xming

Excerpt:

The PC interacts with the server through the X-windows system, forwarding the display from the server to the PC. Software must be installed on the PC to make this link work and the best software (so far) for this task is the PuTTy terminal emulator and the Xming X-window client.

PuTTy can be downloaded from https://www.chiark.greenend.org.uk/~sgtatham/putty/latest.html

Xming can be downloaded from http://sourceforge.net/project/downloading.php?group_id=156984&filename=Xming-6-9-0-31-setup.exe

Once Xming is installed, run the application called 'XLaunch' and verify that the settings are:

1)  Display Settings:  Multiple Windows
2)  Session Type:  Start no client
3)  Additional Parameters:  Check Clipboard box

Then in your PuTTY session you can turn on the X11: Enable X11 Forwarding

So then save that, and every time that session is invoked you will get a GUI connection to Ubuntu, as long as Xming is running.

Xming is verified by the visible icon in the lower right of the screen like so:

In the Xlaunch settings it is selected to not run on startup, so when you don't see that icon then click on Start, type xming and press enter and it will start the x-server and show the icon.

Now, when you make the connection, then you can see

pi@PRIME5:~$ echo $TERM
xterm

The leafpad editor, gnome-system-monitor, etc., work over the link via the Xming server on Windows.

It is easy to pull up nautilus and browse to

/usr/share/applications

to get any of the installed system commands, as shown here:

Voila, X11 via SSH from Windows to Ubuntu.

Related Solutions

Ubuntu – ssh no longer allows public key authentication

If public key authentication doesn't work: make sure that on the server side, your home directory (~), the ~/.ssh directory, and the ~/.ssh/authorized_keys file, are all writable only by their owner. In particular, none of them must be writable by the group (even if the user is alone in the group). chmod 755 or chmod 700 is ok, chmod 770 is not.

What to check when something is wrong:

Run ssh -vvv to see a lot of debugging output. If you post a question asking why you can't connect with ssh, include this output (you may want to anonymize host and user names).
If you can, check the server logs in /var/log/auth.log.
If public key authentication isn't working, check the permissions again, especially the group bit (see above).

Ubuntu – How to get SSH server to work with putty client

This might sound a little obvious, but you need to setup puTTY for ssh, it can do multiple protocols. Under category Session:

Hostname: <remote IP>
Connection Type: ssh
Port: <should default to 22>

Note if you moved the port from he default, you'd have to specify it in your linux connection too.

Next down in Category Connection->SSH check that preferred SSH is set to "2" or "2 only" (your config shows two support and it's a better choice than 1)

Finally puTTY can store information in it's own log which might illuminate the problem click on the Session->Logging category to find out where the file is, set logging to "All session output" and see what shows up.

The error your getting shows the remote server isn't even establishing a connection, which means:

You have the wrong IP
You have the wrong port
There's a firewall on the remote server preventing connections from this box
There's an SSH setting preventing your specific host from connecting (as harish.venkat mentioned)

Best Answer

Related Solutions

Ubuntu – ssh no longer allows public key authentication

Ubuntu – How to get SSH server to work with putty client

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