Message: 2
Date: Thu, 30 Sep 2004 10:53:28 -0700
From: Brent Ware <email@hidden>
Subject: Re: display exporting from an OS X box
To: email@hidden
Message-ID: <email@hidden>
Content-Type: text/plain; charset=US-ASCII; format=flowed
Sorry about the previous blank reply, hit the wrong button.
However, from what I read in the man pages, ssh -X hostname ought to be
all that is necessary. Remote display between Macs and linux hasn't
been working for me for a while either (it works with local Suns). I
don't know whether this is due to something Apple has done or something
I had done - I had figured the latter, since it works with the Suns.
But I can't open an X window from my G5 to my laptop either. I get an
"Error: Can't open display xxx.xxx.xxx.xxx:0"
from "man ssh"
X11 and TCP forwarding
If the ForwardX11 variable is set to ``yes'' (or, see the
description of
the -X and -x options described later) and the user is using X11
(the
DISPLAY environment variable is set), the connection to the X11
display
is automatically forwarded to the remote side in such a way that
any X11
programs started from the shell (or command) will go through the
encrypted channel, and the connection to the real X server will
be
made
from the local machine. The user should not manually set
DISPLAY.
For-
warding of X11 connections can be configured on the command line
or in
configuration files.
The DISPLAY value set by ssh will point to the server machine,
but
with a
display number greater than zero. This is normal, and happens
because
ssh creates a ``proxy'' X server on the server machine for
forwarding the
connections over the encrypted channel.
ssh will also automatically set up Xauthority data on the server
machine.
For this purpose, it will generate a random authorization cookie,
store
it in Xauthority on the server, and verify that any forwarded
connections
carry this cookie and replace it by the real cookie when the
connection
is opened. The real authentication cookie is never sent to the
server
machine (and no cookies are sent in the plain).
-X Enables X11 forwarding. This can also be specified on a
per-host
basis in a configuration file.
X11 forwarding should be enabled with caution. Users
with
the
ability to bypass file permissions on the remote host
(for
the
user's X authorization database) can access the local X11
display
through the forwarded connection. An attacker may then
be
able
to perform activities such as keystroke monitoring.
