OCI: How to Enable X11 Forwarding on an Oracle Linux

 OCI: How to Enable X11 Forwarding on an Oracle Linux 7

I was configuring one of the Oracle Linux 7 server to install Oracle, which would require the use of an X11 forwarded session, So i need to Configure the X11 forwarding on my server. I'm sharing the Procedure i need to follow to get it done.

Step 1.  Install the xorg-x11-xauth package (if it is not already installed). For example:

 yum install xorg-x11-xauth

Step 2:  Enable X11 Fowarding Settings

This is an option to configure inside your SSHD Deamon settings.

# vim /etc/ssh/sshd_config

 X11Forwarding yes

save and exit

Step 3: Restart SSH Service

The SSH service should be restarted to apply the change configuration.

 systemctl restart sshd

Connect From Windows

1. Connect through Putty or other tool as you like.

2. Enable X11

3. Start the session

Connect From  Linux

 ssh -X root@remote-server

Bonus Tip:

If you still can not make the X11 working, then make is to turn off the setting X11UseLocalhost. So part of your configuration would likely look like this:

X11Forwarding yes
#X11DisplayOffset 10
X11UseLocalhost no

After that restart/reload the SSH daemon.
# systemctl reload sshd
# systemctl restart sshd

If you want to X11 forwarding for another user after switch user (su) then please follow the below procedure:

Say it's working for user1 and you want to use it for user2

For user1:
$ xauth list $DISPLAY
<output1>
$ echo $DISPLAY
<outoput2>
Switch to other user , i.e user2
$ xauth add <output1> 
$ export DISPLAY=<output2>

Try:

$ xclock