Xming debian can’t open display

x11xmingxorg

I followed numerous guides for setup and even more "can't open display" error solution, but still can't find what's wrong.
First, on VPS Debian Squeeze I installed xserver-xorg-core and xauth.

Then on Windows 7 installed xming 6.9.0.31.
Then configured putty 2012-11-09:r9690
This is putty config:

putty config

sshd_config on VPS is set to:

X11Forwarding yes
X11DisplayOffset 10
X11UseLocalhost yes

Xauthority file is created in ~/.Xauthority. $DISPLAY is localhost:10.0

I first start xming, then connect with putty.

When I type xlogo I get Error: Can't open display: localhost:10.0.

I put VPS's IP in x0.hosts in xming folder. Tried to change DISPLAY to my IP, :0, localhost:0… I can't even remember the combinations. Tried to put localhost:0 in putty config. I even changed the order of lines in /etc/hosts as I saw in one answer, but nothing works.

Update:
This is putty eventlog:

2013-03-03 15:58:14 Looking up host "IP"
2013-03-03 15:58:14 Connecting to IP port 22
2013-03-03 15:58:14 Server version: SSH-2.0-OpenSSH_5.5p1 Debian-6+squeeze2
2013-03-03 15:58:14 Using SSH protocol version 2
2013-03-03 15:58:14 We claim version: SSH-2.0-PuTTY_Snapshot_2012_11_09:r9690
2013-03-03 15:58:14 Doing Diffie-Hellman group exchange
2013-03-03 15:58:14 Doing Diffie-Hellman key exchange with hash SHA-256
2013-03-03 15:58:15 Host key fingerprint is:
2013-03-03 15:58:15 ssh-rsa 2048 3f:6e:7d:6c:14:6a:3e:18:0d:d4:05:c9:b2:60:d3:00
2013-03-03 15:58:15 Initialised AES-256 SDCTR client->server encryption
2013-03-03 15:58:15 Initialised HMAC-SHA1 client->server MAC algorithm
2013-03-03 15:58:15 Initialised AES-256 SDCTR server->client encryption
2013-03-03 15:58:15 Initialised HMAC-SHA1 server->client MAC algorithm
2013-03-03 15:58:19 Sent password
2013-03-03 15:58:19 Access granted
2013-03-03 15:58:19 Opening session as main channel
2013-03-03 15:58:19 Opened main channel
2013-03-03 15:58:19 Requesting X11 forwarding
2013-03-03 15:58:20 X11 forwarding enabled
2013-03-03 15:58:20 Allocated pty (ospeed 38400bps, ispeed 38400bps)
2013-03-03 15:58:20 Started a shell/command

Where can I check elsewhere?
Any solution to this?

Best Answer

Check if Windows firewall is blocking TCP on localhost:6010.

Try the following little procedure to check if you can connect to the remote X-server (Xming) after setting up an SSH session with PuTTY. Notice port 60xx where xx is identical to the number you find in echo $DISPLAY:

$ echo $DISPLAY 
localhost:10.0
$ netstat -an | grep 6010
tcp        0      0 127.0.0.1:6010          0.0.0.0:*               LISTEN     
tcp6       0      0 ::1:6010                :::*                    LISTEN     
$ telnet 127.0.0.1:6010
telnet: could not resolve 127.0.0.1:6010/telnet: Name or service not known
$ telnet 127.0.0.1 6010
Trying 127.0.0.1...
Connected to 127.0.0.1.
Escape character is '^]'.
^]
telnet> quit
Connection closed.

When the X-server cannot be reached this is what happens:

$ telnet 127.0.0.1 6011
Trying 127.0.0.1...
telnet: Unable to connect to remote host: Connection refused

Related Solutions

Debian – emacs can’t open display

Given the additional info, I guess that your emacsclient is connecting to the "wrong" emacs server. (Or better, the first one that was started: subsequent invocations of emacs --daemon will fail to start the server since the communication socket is already in use.) If the emacs daemon was started in a previous X session, then it's using the wrong credentials for connecting to the X display and thus fails.

You can find out which emacs process is running the server by connecting to it in non-graphics/tty mode; run emacsclient in a terminal with the -nw option:

emacsclient -nw

You can kill a running emacs by having it run LISP code through emacsclient:

emacsclient -t --eval '(progn (server-save-buffers-kill-terminal 1) (save-buffers-kill-emacs 1))'

where:

the -t option (alias for -nw or --tty) is to avoid Emacs connecting to the X display;
the server-save-buffers-kill-terminal detaches the emacsclient before you tell Emacs to stop (otherwise it will issue a confirmation prompt);
the save-buffers-kill-emacs function is what is normally invoked by C-x C-c, argument 1 tells Emacs not to ask for confirmation.

In addition, I guess the reason you are having so many emacs --daemon running is that you invoke emacsclient with the --alternate-editor="" option: the man page emacsclient(1) states that:

If the value of (the alternate) EDITOR is the empty string, then Emacs is started in daemon mode and emacsclient will try to connect to it.

It could be a better option to start emacs --daemon from your X session startup script (e.g., .gnomerc or the GNOME session configutation) so that the session manager will take care of killing the emacs daemon when the session terminates.

X11 forwarding does not work if su to another user

The below steps should fix the issue for you.

Say it's working for user1 and you want to use it for user2

For user1:

$ xauth list $DISPLAY
<output1>
$ echo $DISPLAY
<outoput2>

Switch to other user , i.e user2

$ xauth add <output1> 
$ export DISPLAY=<output2>

Try:

$ xclock

Best Answer

Related Solutions

Debian – emacs can’t open display

X11 forwarding does not work if su to another user

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