How to fix MobaXterm X11-forwarding disabled or not supported by server

Learn how to troubleshoot and resolve the ‘X11-forwarding disabled or not supported by server’ error in MobaXterm. Find solutions and tips to enable X11 forwarding for a smoother remote desktop experience.

x11-forwarding ✘ (disabled or not supported by server), you can solve this problem by adding value in /etc/ssh/sshd_config file.

What is MobaXterm X11 forwarding?

MobaXterm X11-forwarding is a feature that allows a user to run graphical applications on a remote Linux or Unix server and have the graphical output displayed on their local computer. X11 forwarding is a secure method of remotely accessing a graphical user interface (GUI) over a network connection.

While using SSH mode to connect some Linux servers: –

For some Server terminal, MobaXterm shows “X11-forwarding: ✔ (remote display is forwarded through SSH)” that means you can start GUI Application.

For some Server Terminal, MobaXterm shows “X11-forwarding: ✘ (disabled or not supported by server)” That means you can’t use GUI Application and you need to configure sshd_config and ssh_config file on that server.

Solution: –

Ensure xorg-x11-xauth is installed

1. sudo vi /etc/ssh/sshd_config
2. Search for X11Forwarding, X11DisplayOffset and X11UseLocalhost
3. Remove the # sign from each parameter if exists. and set value as below mentioned.
   AllowTcpForwarding yes
X11Forwarding yes
X11DisplayOffset 10
X11UseLocalhost yes
4. Save it
5. Next run this: sudo vi /etc/ssh/ssh_config
6. Search for ForwardX11
7. If there is an found sign, “#”, in front of the parameter, remove it.
8. It should be ForwardX11 yes
9. Save the changes
10. Next make sure sshd is enabled for example: –
    sudo systemctl enable sshd
11. Now start the service
    sudo systemctl start sshd

Configuring DISPLAY variable

Once completed configuration of ssh_config then you need to configure Display variable,
follow the below steps.

Step 1. Move the mouse cursor to the top right corner where it says X server

It will display the IP address of where is going to forward the X11.

Step 2. Run the following command: –
export DISPLAY=<IP_FROM_STEP1>:0.0
echo $DISPLAY
It shows variable is set.

Step 3. Execute below command to check:
xclock

In above image you can see that GUI Clock is open on SSH Terminal. Now you can open application as GUI.