Every time I initiate an ssh connection from my Mac to a Linux (Debian) I do get this warning:

No xauth data; using fake authentication data for X11 forwarding.

This also happens for tools that are using ssh, like git or mercurial.

I just want to make a local change to my system in order to prevent this from appearing.

Note: I do have X11 server (XQuartz 2.7.3 (xorg-server 1.12.4)) on my Mac OS X (10.8.1) and it is working properly, I can successfully start clock locally or remotely.

  • 1
    What command are you using to ssh? – DerfK Aug 30 '12 at 14:43
  • @DerfK just ssh hostname but in my ~/.ssh/config I added ForwardX11 yes some time ago. Still this is something that I do want to have there. – sorin Aug 30 '12 at 14:45
  • Using Ubuntu 16.04 LTS (August 2017) I give up. Bottom line is that even though it gives the error, it works. I use ssh -Y hostname from Linux, and ssh -x hostname when using OpenSSH on Windows. – SDsolar Aug 31 '17 at 5:55

None of the posted solutions worked for me. My client (desktop) system is running macOS 10.12.5 (Sierra). I added -v to the options for the ssh command and it told me,

debug1: No xauth program.

which means it doesn't have a correct path to the xauth program. (On this version of macOS the path to xauth is nonstandard.) The solution was to add this line to /etc/ssh/ssh_config (may be /etc/ssh/config in some setups) or in ~/.ssh/config (if you don't have admin rights):

XAuthLocation /opt/X11/bin/xauth

Now the warning message is gone.

  • 10
    OMG. Years I’ve been trying to find a solution, and this worked. Years I say! Note that I did this by adding that line under the Host * entry in my ~/.ssh/config file instead of editing /etc/ssh/ssh_config. The only documentation I found for this was in man sshd_config. – Demitri Jul 10 '17 at 6:07
  • This worked for me as well. I understand that at the moment XQuartz is not being well maintained due to lack of funding. So I think porting issues like this are actually fewer than I would expect. – AlanObject Jul 23 '17 at 17:09
  • Finally worked!!! – thuzhf Sep 29 '17 at 14:57
  • On High Sierra; this is the one that worked for me too. – mklein9 Mar 10 '18 at 23:52
  • 1
    Note you may experience this issue even when your shell can find xauth in your PATH! I guess the ssh client is sanitizing your PATH for security reasons? – MarcH May 24 '18 at 15:55

Found the cause, my ~/.ssh/config was incomplete, you need both:

Host *
    ForwardAgent yes
    ForwardX11 yes

My mistake was that I included only the ForwardX11 option.

  • 12
    I'm not sure why this is needed/relevant. ForwardAgent is used to allow keys cached in ssh-agent to pass through multiple nested SSH connections. It should not have any relevance to X11. And fwiw, according to some, it's not a good idea security-wise: heipei.github.io/2015/02/26/… – underscore_d Sep 24 '15 at 21:08
  • 2
    That does not sound right, what helps is to actually turn off X11 forwarding or fix the xauth configuration to set it up. It is not related to ssh agents. – eckes Sep 22 '17 at 6:42
  • This solution did not work for me. – David M. Karr Jan 24 at 21:23

As noted, it seems that xauth on OS X Yosemite has regressed to an old version that doesn't work with XQuartz's $DISPLAY setting:

% xauth -V
% xauth generate $DISPLAY .
xauth: (argv):1:  bad display name "/private/tmp/com.apple.launchd(...)/org.macosforge.xquartz:0" in "add" command
  • 1
    I tested the same lines on OS X 10.11, and I do not get any error. Still same version of XQuartz. – sorin Mar 1 '16 at 11:48
  • @guest Your xauth generate $DISPLAY . command worked on my Mac OS X High Sierra (10.13), and it solved my No xauth data; using fake authentication data for X11 forwarding. pb. – SebMa Aug 10 '18 at 16:13

Letting Ubuntu bash on Windows 10 run ssh -X to get a GUI environment on a remote server

  • First

Install all the following. On Window, install Xming. On Ubuntu bash, use sudo apt install to install ssh xauth xorg.

sudo apt install ssh xauth xorg
  • Second

Go to the folder contains ssh_config file, mine is /etc/ssh.

  • Third

Edit ssh_config as administrator(USE sudo). Inside ssh_config, remove the hash # in the lines ForwardAgent, ForwardX11, ForwardX11Trusted, and set the corresponding arguments to yes.

# /etc/ssh/ssh_config

Host *
    ForwardAgent yes
    ForwardX11 yes
    ForwardX11Trusted yes
  • Forth

In ssh_config file, remove the front hash # before Port 22 and Protocol 2, and also append a new line at the end of the file to state the xauth file location, XauthLocation /usr/bin/xauth, remember write your own path of xauth file.

# /etc/ssh/ssh_config

#   IdentifyFile ...
    Port 22
    Protocol 2
#   Cipher 3des
#   ...
#   ...
    GSSAPIDelegateCredentials no
    XauthLocation /usr/bin/xauth
  • Fifth

Now since we are done editing ssh_config file, save it when we leave the editor. Now go to folder ~ or $HOME, append export DISPLAY=localhost:0 to your .bashrc file and save it.

# ~/.bashrc
export DISPLAY=localhost:0
  • Last

We are almost done. Restart your bash shell, open your Xming program and use ssh -X yourusername@yourhost. Then enjoy the GUI environment.

ssh -X yourusername@yourhost

The problem is also in Ubuntu subsystem on Windows, and the link is at


Note: the linked text includes 2 typos (XauthLocaion instead of XauthLocation)

  • The question isn't about Windows. – kasperd Sep 22 '17 at 7:53
  • On MacOS it is almost the same, the differences are instead of Xming, we should get XQuartz, and the ssh_config file is in a different location, mine is /private/etc/ssh. – DestinyOne Sep 22 '17 at 15:45
  • And also, the last line for ssh_config will be: XAuthLocation /opt/X11/bin/xauth – DestinyOne Sep 22 '17 at 15:58
  • 2
    Edit needed: XauthLocaion -> XauthLocation (that edit is too small for me to make). – echristopherson Mar 3 '18 at 4:05
  • Besides installing xming, ssh,xauth, and xorg (step 1), the only thing needed for me was export DISPLAY=localhost:0 – Eponymous Mar 8 '18 at 3:35

There is a bug in MacOS at the moment. I came across this too. The fix for me involved adding the following to my .bash_profile

dispdir=`dirname $DISPLAY`
dispfile=`basename $DISPLAY`
if [ -e $DISPLAY -a "$dispfile" = "org.x:0" ]; then
  mv $DISPLAY $dispnew
export DISPLAY=$dispnew

Essentially the name for the file pipe associated with your X root can't be handled correctly, and thus needs correction. :-)

  • I doubt this would solve the error in GUI OS X apps, like SourceTree. – sorin Mar 1 '16 at 11:49
  • Confirming it does work on Sierra for running emacs using X - as the Mac is the server. this should work broadly in cases where the client is on a remote machine – Mark Mullin Dec 18 '16 at 16:24


XAuthLocation /opt/local/bin/xauth in ~/.ssh/config

in my macOS Sierra 10.12.6 worked for me. A small change from answer 7).


i just removed ~/.Xauthority (destination machine) from my root folder and ssh -X again and ik worked.

  • I can confirm this is an answer on Mac OS Sierra 10.12.4. Removing ~/.Xauthority on SSH server does the trick: ~$ mv ~/.Xauthority ~/.Xauthority.bak A new magic cookie was automatically put back in ~/.Xauthority once I logged in again. No Bash scripting is required at all. – Kenneth Pegasus May 31 '17 at 23:45

In my case it was the problem of .Xauthority containing the Magic cookie not forwarded, Fabby on http://askubuntu.com/questions/571116/ recommends on 2014-11-14 to add this line at the end of the .bashrc or . profile to allow forwarding of xauth keys between users when calling su:

export $(dbus-launch)

I added also previously:

export XAUTHORITY=~/.Xauthority 

to ensure remote called with ssh -X ̍@ will find it.

In my case .Xauthority is a symlink to original user /home//.Xauthority I su from...

  cd /home/<child_user>;ln -sf /home/<parent_user>/.Xauthority .xAuthority

with correct rights:

  sudo chown <parent_user> /home/<parent_user>/.profile
  chmod a+rw /home/<parent_user>/.profile 

so it is accessible to and to . will be able to trigger apps on and display X-windowed result on its local screen throughout proxy account !

TIP : Check xauth list...if reflects magic cookie on .


I would add this as a comment, but I don't have enough rep. Adding one more line to sorin's solution worked for me.

Open your ssh config file with vim ~/.ssh/config Then add these lines to it:

Host *
    ForwardAgent yes
    ForwardX11 yes
    XAuthLocation /opt/X11/bin/xauth

You can double check your xauth location with:

which xauth
  • Not sure if this would really work because xauth location would be different on each remote machine. Yours looks like a MacOS one, but Linux has it in different location. I mostly started to disable ForwardX11 completly because I almost never user it. – sorin Feb 23 at 8:23

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