But I also have sudo privs, and for a lot of server management I need to be able to run some X apps (eg Emacs) as root. I do this on a lot of other servers running RHEL{4|5} by becoming root, exiting, and running the app, thereby using the sticky-time of the X authentication, eg

$ sudo su -
[my password]
# exit
$ sudo system-config-printer &
$

This doesn’t work on the new machine: I get
X11 connection rejected because of wrong authentication.

I can’t see what I need to change: X11 forwarding is set, and all of the above suggestions.

Also, from another forum, I solved my issue by adding XAUTHORITY=~/.Xauthority environment variable, so this worked: “XAUTHORITY=~/.Xauthority DISPLAY=localhost:10.0 gnome-terminal” while this: “DISPLAY=localhost:10.0 gnome-terminal” got me an error that the display couldn’t be opened on the client with the server side giving the error ” X11 connection rejected because of wrong authentication.”. I hope this information is helpful for someone.

From localmachine:
ssh -R 6007:localhost:6000 remotemachine
This creates a port-forward that maps requests to port 6007 on remotemachine to port 6000 on localmachine. The default X server port (:0.0) is shorthand for 6000.

Then on the hostmachine:
export DISPLAY=localhost:7.0
This maps all display requests to port 6007 on the remotemachine

Instead of typing this every time, this can be automated by adding entries to files in ~/.ssh:

localmachine:~/.ssh/config
Host remotemachine
RemoteForward 6007 localhost:6000

remotemachine:~/.ssh/environment
DISPLAY=localhost:7.0

error message:
“X11 connection rejected because of wrong authentication.
The application ‘gedit’ lost its connection to the display localhost:13.0;
most likely the X server was shut down or you killed/destroyed
the application.”

does anyone have any other ideas on this?

Thanks

Thank you.

Of course I skipped the “Check your drive space” line believing I had lots of space, and went through and checked everything else first, before running a df and seeing that, in fact, I HAD run out of space.

Clearing out an out of control log file fixed the issue in a jiffy.

$ xauth list $DISPLAY

You’ll get something like
machine1:10 mit-magic-cookie-1 4d22408a71a55b41ccd1657d377923ae

Now ssh to the other machine (machine2) and tell it what the cookie is by adding it to the authentication list.

$ xauth add :10 MIT-MAGIC-COOKIE-1 4d22408a71a55b41ccd1657d377923ae

$ echo $DISPLAY

The echo command should show machine1

The fix was to add
–
X11UseLocalhost yes
–
to your /etc/ssh/sshd.config

This did the trick for me – at least.

I don’t know if it ever wasn’t working, for sure. But it is working now. There should be no reason to use the -Y flag (IMHO). It certainly shouldn’t be your first choice, as the -Y flag enables “trusted” forwarding, which are NOT subjected to the X11 SECURITY extension controls. This could leave your session vulnerable to keystroke monitoring.

Fly safe – Metajunkie

I fixed the problem by add -Y function in my ssh command :
—–
ssh -X -Y user@host
—–

(I’m sorry if my language isn’t clear, I’m not very good in english :/ )

Not sure why Apple broke convention here, but I think this is the fix you are looking for.