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: –

Setp 1: Ensure xorg-x11-xauth and xclock

Step 2: configure X11 forwarding.

sudo vi /etc/ssh/sshd_config

sudo vi /etc/ssh/sshd_config

1. Search for X11Forwarding, X11DisplayOffset and X11UseLocalhost
2. Remove the # sign from each parameter if exists. and set value as below mentioned.
   AllowTcpForwarding yes
X11Forwarding yes
X11DisplayOffset 10
X11UseLocalhost yes
3. Save it

Next run this: sudo vi /etc/ssh/ssh_config

sudo vi /etc/ssh/ssh_config

1. Search for ForwardX11
2. If there is an found sign, “#”, in front of the parameter, remove it.
3. It should be ForwardX11 yes
4. Save the changes.

Next make sure sshd is enabled for example: –

sudo systemctl enable sshd

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 test: –

xclock

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

See Also

How to enable X11 forwarding in RHEL, SUSE and Amazon Linux