Ask Ubuntu is a question and answer site for Ubuntu users and developers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

When I SSH to a remote box

$ ssh -X remotebox

then start firefox on the remote box

remotebox$ firefox

and I have firefox running on my local machine, a local firefox window will open. no firefox process is running on the remote box.

If firefox is not running on my local machine then a remote firefox window will open.

Why is it opening a local firefox window? How can i prevent that?

Here some more information of my local system.

Linux lesmana-laptop 2.6.32-24-generic #42-Ubuntu SMP Fri Aug 20 14:24:04 UTC 2010 i686 GNU/Linux

No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 10.04.1 LTS
Release:    10.04
Codename:   lucid


Mozilla Firefox 3.6.8, Copyright (c) 1998 - 2010

Information of remotebox.

Linux dxray #1 SMP 2009-08-14 02:09:16 +0200 x86_64 x86_64 x86_64 GNU/Linux

LSB Version:    core-2.0-noarch:core-3.0-noarch:core-2.0-x86_64:core-3.0-x86_64:desktop-3.1-amd64:desktop-3.1-noarch:graphics-2.0-amd64:graphics-2.0-noarch:graphics-3.1-amd64:graphics-3.1-noarch
Distributor ID: SUSE LINUX
Description:    openSUSE 10.3 (X86-64)
Release:    10.3
Codename:   n/a


Mozilla Firefox 3.0.14, Copyright (c) 1998 - 2009

The following command starts a remote firefox session with a remote firefox window.

remotebox$ firefox -no-remote

The following command produces a brief delay, then drops back to prompt and a local firefox window pops up. No firefox process running on the remotebox.

remotebox$ firefox

Information of remotebox2.

Linux marvin 2.6.31-22-generic #60-Ubuntu SMP Thu May 27 00:22:23 UTC 2010 i686 GNU/Linux

No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 9.10
Release:    9.10
Codename:   karmic


Mozilla Firefox 3.6.8, Copyright (c) 1998 - 2010

The following command on remotebox2 starts a remote firefox session as expected.

remotebox2$ firefox

I do not know why firefox on remotebox2 starts a remote session instead of a local session.

share|improve this question
Can we get the contents of the $DISPLAY variable on both the local and the remote machine? – aperson Sep 3 '10 at 8:13
@aperson, updated question. – lesmana Sep 3 '10 at 10:33
Thanks, the $DISPLAY doesn't seem to be an issue, ssh appears to be setting things up properly. – aperson Sep 3 '10 at 18:46
up vote 30 down vote accepted

besides firefox -no-remote another parameter is firefox -no-xshm which reveals the technique used to make it work.

X11 shared memory is an interprocess communication technique which can be used by all applications connected to a given x server session. It can be used to perform drag & drop, and other kind of desktop interaction.

It can be (and is) used also to implement "open once" applications, in order to reduce the footprint (or the number of windows).

Since the X11 protocol is network transparent the "shared memory" is extended also to remote X11 clients.

share|improve this answer
Is there any way I can make x not do this? I am looking to containerize a video game/wine setup for easy distribution, but this is causing me headaches, because it will cause unspecified behaviour depending on what the user of the container has installed and running. I am using this solution to do the x forwarding: and would like to simply make sure the container never shares memory with the host. – Sir Substance Jan 6 '15 at 0:35
It doesn't work for me – Bob Ebert Mar 10 at 3:40

Try firefox -no-remote

share|improve this answer
this works in opening a remote firefox window. but i still do not understand why a remote command can trigger a local firefox window to open. – lesmana Sep 3 '10 at 6:53
@lesmana this may be due to x11-forwarding - if that is setup in the sshd_config you may have a situation where it's being executed and tunneled back through. – Marco Ceppi Sep 4 '10 at 0:08

Note, I did dome digging as this was bugging me and you can also just add:


to your profile.

share|improve this answer

You can try this, when you connected to machine (ssh user@host; note: without -X option), first type the follow command

export DISPLAY=:0 

this would change the default display to that of the current desktop screen. And then just type


to have firefox spawned on the desktop window. Ensure that you have logged into the desktop, without which (no logins) you will get the following error;

firefox: cannot connect to X server :0

This method would work for locked desktops as well. Please ensure that you have logged in on the desktop and the ssh shell with the same username.

When there are multiple desktop sessions, each session is identified by a different number as :0, :1, :2, etc.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.