Hi,

I'm trying to get X11 forwarding from a Solaris (sparc) Workstation to
a linux (Ubuntu x86) machine. The solaris machine supports rlogin and X
forwarding works between Solaris machine to Solaris machine. After
logging into the solaris workstation I setenv Display to
<linuxmachine>:0.0 and run a X app on the solaris machine. After a few
seconds it reports that it cannot open display on remote (linux)
machine.

XView error: Cannot open connection to window server:
<linuxmachine>:0.0 (Server package)

I have rsh server on linux machine do I need anything else installed to
make X forwarding to work? I have triex xhost + on linux machine that
doesn't help either. Iptables policy on the linux machine are ACCEPT.
What could be preventing X forwarding?

Any help / pointers would be appreciated.

Thanks.

arduous@gmail.com wrote:
> Hi,
> 
> I'm trying to get X11 forwarding from a Solaris (sparc) Workstation to
> a linux (Ubuntu x86) machine. The solaris machine supports rlogin and X
> forwarding works between Solaris machine to Solaris machine. After
> logging into the solaris workstation I setenv Display to
> <linuxmachine>:0.0 and run a X app on the solaris machine. After a few
> seconds it reports that it cannot open display on remote (linux)
> machine.
> 
> XView error: Cannot open connection to window server:
> <linuxmachine>:0.0 (Server package)
> 
> I have rsh server on linux machine do I need anything else installed to
> make X forwarding to work? I have triex xhost + on linux machine that
> doesn't help either. Iptables policy on the linux machine are ACCEPT.
> What could be preventing X forwarding?
> 
> Any help / pointers would be appreciated.
> 
> Thanks.
> 
On the linux machine, can you try:
$ ssh -X solaris_machine -l your_user_id

Once you get on the solaris machine, the DISPLAY variable should have 
been set for you already, you can run
$ echo $DISPLAY
to check what value it is set to...

Then you can run xclock or some other x programs to check if the display 
works.

HTH

Thanks for the reply,

> On the linux machine, can you try:
> $ ssh -X solaris_machine -l your_user_id

>From my linux machine I can rlogin to the remote sun machine but looks
like being a primitive protocol, rlogin doesn't set the display.


> Once you get on the solaris machine, the DISPLAY variable should have
> been set for you already, you can run
> $ echo $DISPLAY
> to check what value it is set to...

grebe# echo $DISPLAY
toucan:0.0


>
> Then you can run xclock or some other x programs to check if the display
> works.

grebe# xclock
Error: Can't open display: toucan:0.0


toucan = linux machine
grebe = Sun Solaris sparc

arduous@gmail.com wrote:
> Thanks for the reply,
> 
> 
>>On the linux machine, can you try:
>>$ ssh -X solaris_machine -l your_user_id
> 
> 
>>From my linux machine I can rlogin to the remote sun machine but looks
> like being a primitive protocol, rlogin doesn't set the display.
> 
> 
> 
>>Once you get on the solaris machine, the DISPLAY variable should have
>>been set for you already, you can run
>>$ echo $DISPLAY
>>to check what value it is set to...
> 
> 
> grebe# echo $DISPLAY
> toucan:0.0
> 
> 
> 
>>Then you can run xclock or some other x programs to check if the display
>>works.
> 
> 
> grebe# xclock
> Error: Can't open display: toucan:0.0
> 
> 
> toucan = linux machine
> grebe = Sun Solaris sparc
> 
It may be obvious, but have you set xhost on the linux machine to the 
server (xhost +server)?

-- 
God's Blessings and love

	Deacon Gary Meerschaert   <'}}}}><

Madison Heights, MI
Archdiocese of Detroit

Don't give up on your dreams.
	Wait a bit and they'll give up on you
	and you can start again without all of that guilt.

Gary.meerschaert@gmail.com

arduous@gmail.com wrote:
> Hi,
>
> I'm trying to get X11 forwarding from a Solaris (sparc) Workstation to
> a linux (Ubuntu x86) machine. The solaris machine supports rlogin and X
> forwarding works between Solaris machine to Solaris machine. After
> logging into the solaris workstation I setenv Display to
> <linuxmachine>:0.0 and run a X app on the solaris machine. After a few
> seconds it reports that it cannot open display on remote (linux)
> machine.

Assuming you have run xhost <IP> or xhost + on the Linux machine:

1. First try simple telnet using IP numbers instead of host name.
>From my Linux box (192.168.1.101) when I log on to
Solaris (IP 192.168.1.100) I do:
% telnet 192.168.1.100
Trying 192.168.1.100...
Connected to 192.168.1.100 (192.168.1.100).
:
Last login: Fri Jul 21 22:14:37 from 192.168.1.101
Sun Microsystems Inc.   SunOS 5.10      Generic January 2005
% setenv DISPLAY 192.168.1.101:0
% xclock

2 If I use ssh I do:
% ssh -c 3des -l pdl -p 22 192.168.1.100
Password:
Last login: Fri Jul 21 22:16:47 2006 from 192.168.1.101
Sun Microsystems Inc.   SunOS 5.10      Generic January 2005
% echo $DISPLAY
localhost:10.0
% xclock

## In this case I do not need to manually set the DISPLAY variable.
This requires that /etc/ssh/sshd_config has the option:
X11Forwarding yes  (which was default on Solaris)

If  neither of these work there may be some host access control on
the Solaris machine that does not allow the X11 forwarding.
Don't know the corresponding file names in Solaris but on
Linux some services such as sshd, telnetd are controlled by
tcp wrappers /etc/hosts.allow,  /etc/hosts.deny, /etc/xinetd.d/telnet

/Karl

arduous@gmail.com wrote:
> Hi,
> 
> I'm trying to get X11 forwarding from a Solaris (sparc) Workstation to
> a linux (Ubuntu x86) machine. The solaris machine supports rlogin and X
> forwarding works between Solaris machine to Solaris machine. After
> logging into the solaris workstation I setenv Display to
> <linuxmachine>:0.0 and run a X app on the solaris machine. After a few
> seconds it reports that it cannot open display on remote (linux)
> machine.
> 
> XView error: Cannot open connection to window server:
> <linuxmachine>:0.0 (Server package)
> 
> I have rsh server on linux machine do I need anything else installed to
> make X forwarding to work? I have triex xhost + on linux machine that
> doesn't help either. Iptables policy on the linux machine are ACCEPT.
> What could be preventing X forwarding?
> 
> Any help / pointers would be appreciated.
> 
> Thanks.
> 

Probably you have to configure your Linux box to not start its X-Server
with the '-nolisten tcp' option which may be the default setup.

Do a 'ps auxww | grep X' on your Linux box to be sure.

Don't know where you have to configure this. Probably somewhere below
/etc/X11. Do a 'grep -R nolisten /etc/X11' to find out.

Rainer

arduous@gmail.com wrote:
> Hi,
> 
> I'm trying to get X11 forwarding from a Solaris (sparc) Workstation to
> a linux (Ubuntu x86) machine. The solaris machine supports rlogin and X
> forwarding works between Solaris machine to Solaris machine. After
> logging into the solaris workstation I setenv Display to
> <linuxmachine>:0.0 and run a X app on the solaris machine. After a few
> seconds it reports that it cannot open display on remote (linux)
> machine.

The easy and secure way:

linuxbox%  ssh -X username@solarisbox
solarisbox%  xprogram

if it does not work check in the solaris box that sshd is running
and that X11Forwarding is enabled in /etc/ssh/sshd_config; restart
sshd if you change sshd_config

The hard and insecure way:

-check that the linux firewall accepts connections from the solaris box,
X traffic does not go through the "rlogin" channel so *do not* assume
that because rlogin works X should work too.  Then and only then...

linuxbox%  xhost +solarisbox
linuxbox%  rlogin solarisbox
solarisbox%  DISPLAY=linuxbox:0; export DISPLAY (for sh/ksh/bash shell)
solarisbox%  setenv DISPLAY linuxbox:0  (for csh/tcsh shell)
solarisbox%  xprogram

Thanks Karl,

KarlD wrote:
>
> 1. First try simple telnet using IP numbers instead of host name.
> >From my Linux box (192.168.1.101) when I log on to
> Solaris (IP 192.168.1.100) I do:
> % telnet 192.168.1.100
> Trying 192.168.1.100...
> Connected to 192.168.1.100 (192.168.1.100).
> :
> Last login: Fri Jul 21 22:14:37 from 192.168.1.101
> Sun Microsystems Inc.   SunOS 5.10      Generic January 2005
> % setenv DISPLAY 192.168.1.101:0
> % xclock

Here is the session:

root@toucan:~# rlogin grebe
Last login: Fri Jul 21 15:22:49 from toucan
Sun Microsystems Inc.   SunOS 5.8       Generic Patch   October 2001

mail: Invalid permissions on /var/mail/root
grebe# echo $DISPLAY
DISPLAY: Undefined variable
grebe# setenv DISPLAY toucan:0.0
grebe# echo $DISPLAY
toucan:0.0
grebe# xclock
Error: Can't open display: toucan:0.0
grebe#
grebe# ping -s toucan
PING toucan: 56 data bytes
64 bytes from toucan (172.16.101.89): icmp_seq=0. time=0. ms
64 bytes from toucan (172.16.101.89): icmp_seq=1. time=0. ms


> If  neither of these work there may be some host access control on
> the Solaris machine that does not allow the X11 forwarding.
> Don't know the corresponding file names in Solaris but on
> Linux some services such as sshd, telnetd are controlled by
> tcp wrappers /etc/hosts.allow,  /etc/hosts.deny, /etc/xinetd.d/telnet

>From another sun machine I can rlogin to grebe and run xclock after
setting the DISPLAY variable. So there is no access control on grebe.

How should I proceed to troubleshoot this scenario?

Regards,

Thanks Rainer,

I'll try that.

Rainer Beushausen wrote:

> Probably you have to configure your Linux box to not start its X-Server
> with the '-nolisten tcp' option which may be the default setup.
>
> Do a 'ps auxww | grep X' on your Linux box to be sure.
>
> Don't know where you have to configure this. Probably somewhere below
> /etc/X11. Do a 'grep -R nolisten /etc/X11' to find out.
> 
> Rainer

Oscar del Rio wrote:

> The hard and insecure way:
>
> -check that the linux firewall accepts connections from the solaris box,
> X traffic does not go through the "rlogin" channel so *do not* assume
> that because rlogin works X should work too.  Then and only then...
>
> linuxbox%  xhost +solarisbox
> linuxbox%  rlogin solarisbox
> solarisbox%  DISPLAY=linuxbox:0; export DISPLAY (for sh/ksh/bash shell)
> solarisbox%  setenv DISPLAY linuxbox:0  (for csh/tcsh shell)
> solarisbox%  xprogram

Thanks Oscar,

We don't have ssh on the sun boxes for some reason, we only use the
insecure rlogin.

root@toucan:~# xhost +grebe
grebe being added to access control list
root@toucan:~# rlogin grebe
Last login: Mon Jul 24 09:07:34 from toucan
Sun Microsystems Inc.   SunOS 5.8       Generic Patch   October 2001

mail: Invalid permissions on /var/mail/root
grebe# setenv DISPLAY toucan:0.0
grebe# xclock
Error: Can't open display: toucan:0.0


:-(

root@toucan:/etc/X11# ps auxww | grep X
root      4475  1.1 13.7 147532 141000 tty7    Ss+  Jul18  97:35
/usr/bin/X :0 -br -audit 0 -auth /var/lib/gdm/:0.Xauth -nolisten tcp
vt7


Rainer Beushausen wrote:
>
> Probably you have to configure your Linux box to not start its X-Server
> with the '-nolisten tcp' option which may be the default setup.
>
> Do a 'ps auxww | grep X' on your Linux box to be sure.
>
> Don't know where you have to configure this. Probably somewhere below
> /etc/X11. Do a 'grep -R nolisten /etc/X11' to find out.
> 
> Rainer

Arduous wrote:
> root@toucan:/etc/X11# ps auxww | grep X
> root      4475  1.1 13.7 147532 141000 tty7    Ss+  Jul18  97:35
> /usr/bin/X :0 -br -audit 0 -auth /var/lib/gdm/:0.Xauth -nolisten tcp
> vt7
> 

So it's clear now. If you want to have X11-connects over the net
you have to get rid of that '-nolisten tcp' Flag.

Rainer

Thanks Rainer,

I got rid of the nolisten option and now X is listening on port 6000

root@toucan:~# netstat -l |grep -i x11
tcp        0      0 *:x11                   *:*
LISTEN
tcp6       0      0 *:x11                   *:*
LISTEN


but now it started giving a diffrent error:

grebe# setenv DISPLAY toucan:0.0
grebe# xclock
Xlib: connection to "toucan:0.0" refused by server
Xlib: No protocol specified

Error: Can't open display: toucan:0.0

Thanks,



Rainer Beushausen wrote:
> Arduous wrote:
> > root@toucan:/etc/X11# ps auxww | grep X
> > root      4475  1.1 13.7 147532 141000 tty7    Ss+  Jul18  97:35
> > /usr/bin/X :0 -br -audit 0 -auth /var/lib/gdm/:0.Xauth -nolisten tcp
> > vt7
> >
>
> So it's clear now. If you want to have X11-connects over the net
> you have to get rid of that '-nolisten tcp' Flag.
> 
> Rainer

The problem is resolved. I didn't knew that the xhost +<host> command
looses the access list on reboot :-(

The main problem was X11 not listening on port 6000

All is well now. Thanks every one!

Regards.

Rainer Beushausen wrote:

> So it's clear now. If you want to have X11-connects over the net
> you have to get rid of that '-nolisten tcp' Flag.
> 
> Rainer