[KLUG Members] can't open display for remote X app

[bfdamkoehler at worldnet.att.net]

I too have had issues lately. There are two issues that I am aware of.  
First, by default Suse configures X so that only the local machine can 
use it. This is easy to fix but probably won't fix your problem because 
of the second issue. The second issue I am less clear about, and it  
involves differences in behavior between xfree86 X which was used by the 
older distributions and the xorg X which is currently being used.

To turn on remote X support in Suse you can either use the /etc/sysconf 
editor in yast or directly edit /etc/sysconfig/displaymanager and change 
DISPLAYMANAGER_XSEREVER_TCP_PORT_6000_OPEN from "no" to "yes" (you may 
or may not want to alter DISPLAYMANAGER_ROOT_LOGIN_REMOTE  as well).

With xfree86 "xhost +" would fix any problems, and you could always 
specify "DISPLAY=somenode:0" and it would work. If the X server that you 
are displaying on is running xorg you must use a "DISPLAY=localhost:nn" 
type of setting, which requires the use of ssh. If you really want to 
continue to launch X sessions from a telnet session then maybe you 
should investigate xauth (not that I have).  Finally, using an xorg X 
server you can't su from one account to another (on the remote machine) 
and expect your remote X to work with it. I occasionally have problems 
even if I make sure that I have everything as described above. Creating 
another session typically fixes it.








John Pesce wrote:

>Remote X display over ssh works fine. 
>
>I can't remote display anymore when I rsh or telnet.
>
>
>On Sat, 2005-12-17 at 10:22 -0500, Stuart Gillis wrote:
>  
>
>>On your Suse box, edit /etc/ssh/ssh_config
>>
>>Change :
>>
>>#   ForwardX11 no
>>    to
>>ForwardX11 yes
>>
>>That should fix it.
>>
>>Stu
>>
>>
>>On 12/15/05, John Pesce <pescej at sprl.db.erau.edu> wrote:
>>    
>>
>>>Hi,
>>>
>>>I've encountered a wierd and unexpected X error. I guess I've been ssh
>>>-X tunneling for so long I didn't notice until now.
>>>
>>>My older workstations that still run RH9 work as expected. I can xhost
>>>nextbox, telnet or rsh from it into nextbox, set my DISPLAY to other:0,
>>>and run xeyes.
>>>
>>>All my other newer boxes are running Suse 9.3 or RHE have ssh and not
>>>telnet or rsh. We just got a new HP unix box installed for a special
>>>purpose app and it does not have ssh.
>>>On my RHE box I xhost +, and then telnet to the HP, setenv DISPLAY
>>>RHE:0.0 and try and run the app.
>>>I get Error: Can't open display: RHEIP:0
>>>
>>>I thought this was strange so I went to a Suse 9.3 box and tried to do
>>>the same thing with the same error. Then I tried running xeyes on the
>>>Suse 9.3 box and displaying it on another Suse 9.3 box, same error.
>>>
>>>I don't have workstation firewalls. What gives?
>>>Did X add some new feature to disable xhost +?
>>>
>>>I can xhost + on the older RH9 box and telnet to the HP and remote
>>>display ok.
>>>_______________________________________________
>>>Members mailing list
>>>Members at kalamazoolinux.org
>>>
>>>
>>>      
>>>
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>>
>>    
>>
>
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