CentOS - Oct 2011 - C6: ssh X-forwarding does not work

Hi all,

I have C6 i386 with cr repo enabled;

problem is, I can't get x-forwarding to work, xorg-x11-auth rpm is 
installed, have checked sshd config for

#X11Forwarding no
X11Forwarding yes
#X11DisplayOffset 10

Here is a verbose ssh logon, I can't see any difference to a working server:

debug1: Authentication succeeded (password).
debug1: channel 0: new [client-session]
debug3: ssh_session2_open: channel_new: 0
debug2: channel 0: send open
debug1: Entering interactive session.
debug2: callback start
debug2: x11_get_proto: /usr/bin/xauth  list unix:10.0 2>/dev/null
debug1: Requesting X11 forwarding with authentication spoofing.
debug2: channel 0: request x11-req confirm 0
debug2: client_session2_setup: id 0
debug2: channel 0: request pty-req confirm 0

and netstat does not show the open ports in the 60xx range:

# netstat -antp|grep 60
tcp        0      0 192.168.200.31:22           192.168.200.30:58604 
     VERBUNDEN   2537/sshd: xxx [

Display var is not set...:

[root at tr-centos ~]# env|grep -i DISPLAY
[root at tr-centos ~]#

Any obvious mistake?

Thx
Rainer

Hi,

I have a working configuration with CentOS 6. Can you try to set next 
lines in /etc/ssh/sshd_config and restart SSH server please?

#X11Forwarding no
X11Forwarding yes
#X11DisplayOffset 10
X11UseLocalhost yes


In fact I do not have xorg-x11-auth rpm installed:

[root at Carmen ~]# rpm -qa|grep -i xorg-x11-auth
[root at Carmen ~]#

and it works...

Give it a try and let us know.
Regards,

El 26/10/11 11:56, Rainer Traut escribi?:
> Hi all,
>
> I have C6 i386 with cr repo enabled;
>
> problem is, I can't get x-forwarding to work, xorg-x11-auth rpm is
> installed, have checked sshd config for
>
> #X11Forwarding no
> X11Forwarding yes
> #X11DisplayOffset 10
>
> Here is a verbose ssh logon, I can't see any difference to a working
server:
>
> debug1: Authentication succeeded (password).
> debug1: channel 0: new [client-session]
> debug3: ssh_session2_open: channel_new: 0
> debug2: channel 0: send open
> debug1: Entering interactive session.
> debug2: callback start
> debug2: x11_get_proto: /usr/bin/xauth  list unix:10.0 2>/dev/null
> debug1: Requesting X11 forwarding with authentication spoofing.
> debug2: channel 0: request x11-req confirm 0
> debug2: client_session2_setup: id 0
> debug2: channel 0: request pty-req confirm 0
>
> and netstat does not show the open ports in the 60xx range:
>
> # netstat -antp|grep 60
> tcp        0      0 192.168.200.31:22           192.168.200.30:58604
>       VERBUNDEN   2537/sshd: xxx [
>
> Display var is not set...:
>
> [root at tr-centos ~]# env|grep -i DISPLAY
> [root at tr-centos ~]#
>
> Any obvious mistake?
>
> Thx
> Rainer
> _______________________________________________
> CentOS mailing list
> CentOS at centos.org
> http://lists.centos.org/mailman/listinfo/centos
>
>

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On Friday, October 28, 2011 04:10:05 AM Steve Brooks wrote:
> I have a few "sl6.1" worstations that do not have
"xorg-x11-xauth"
> installed and it does *not* seem to appear in the repos. Yet 
> X11-Forwarding works fine.
That's mighty strange, as a basically scratch SL6.1 install here shows:
[root at pe1600sc-2 ~]# repoquery --qf "%-20{repoid} %{name}"
xorg-x11-xauth
sl                   xorg-x11-xauth
[root at pe1600sc-2 ~]# cat /etc/issue
Scientific Linux release 6.1 (Carbon)
Kernel \r on an \m

[root at pe1600sc-2 ~]#

On a CentOS 6.0+CR VM here:

[root at z1-c6 ~]# repoquery --qf "%-20{repoid} %{name}"
xorg-x11-xauth
base                 xorg-x11-xauth
[root at z1-c6 ~]# cat /etc/issue
CentOS Linux release 6.0 (Final)
Kernel \r on an \m

[root at z1-c6 ~]#

I did absolutely nothing special to either of these two boxes (just a basic
installation that included GNOME and other server things (these boxes get used
as remote desktop servers in addition to other duties, so GUI is required), and
X forwarding works fine.  I typically use X forwarding to run a few GUI programs
that are mighty handy, such as palimpsest (GNOME Disk Utility) which puts all in
one place lots and lots of useful information about your disk devices that would
otherwise require many command line invocations to grab.

Both boxes have xorg-x11-xauth installed.

On Saturday, October 29, 2011 07:28:27 AM John Hodrien
wrote:
> On Sat, 29 Oct 2011, John R Pierce wrote:
> > well, there's the subtle clue that the first time you log onto a
> > particular account with X forwarding, xauth prints a message about
> > saving the .Xauth file....
> Sure, but that means you're looking for absence of an info message
(that you
> typically don't care all that much about) to let you know
something's wrong.
> That's very easy to miss.
Sounds to me like something for the CentOS FAQ on the Wiki.....

Q: Why is my X forwarding not working, but the sshd config has it enabled?

A: One possibility is that the xorg-x11-xauth package needs to be installed.

On Saturday, October 29, 2011 07:26:04 PM John Hodrien
wrote:
> ssh tells you when it creates a .Xauthority file for the first time.  Why
does
> it do that? 
Being totally pedantic here, but isn't it /usr/bin/xauth that issues the
message telling that the .Xauthority file has been created?