Failed to forward X11: Network error: connection refused

Question

I have a VPS, OS is CentOS6.3. I want to start startx via PuTTY and Xming.

But this causes this error:

 PuTTY X11 proxy: unable to connect to forwarded X server: Network error: Connection refused 

All condition:

 Using username "root". Authenticating with public key "rsa-key-20150906" from agent Last login: Thu Jan 21 13:53:40 2016 from 222.222.150.82 [ root@mairo ~]# xhost + PuTTY X11 proxy: unable to connect to forwarded X server: Network error: Connection refused xhost: unable to open display "localhost:10.0" [ root@mairo ~]# echo $DISPLAY localhost:10.0 [ root@mairo ~]# gedit PuTTY X11 proxy: unable to connect to forwarded X server: Network error: Connection refused (gedit:6287): Gtk-WARNING **: cannot open display: localhost:10.0 [ root@mairo ~]# 

And here is the Xming magazine:

 Welcome to the Xming X Server Vendor: Colin Harrison Release: 6.9.0.31 FreeType2: 2.3.4 Contact: http://sourceforge.net/forum/?group_id=156984 Xming :10 -multiwindow -clipboard XdmcpRegisterConnection: newAddress 192.168.139.1 winAdjustVideoModeShadowGDI - Using Windows display depth of 32 bits per pixel winAllocateFBShadowGDI - Creating DIB with width: 1366 height: 768 depth: 32 winInitVisualsShadowGDI - Masks 00ff0000 0000ff00 000000ff BPRGB 8 d 24 bpp 32 glWinInitVisuals:1596: glWinInitVisuals glWinInitVisualConfigs:1503: glWinInitVisualConfigs glWinSetVisualConfigs:1581: glWinSetVisualConfigs init_visuals:1055: init_visuals null screen fn ReparentWindow null screen fn RestackWindow InitQueue - Calling pthread_mutex_init InitQueue - pthread_mutex_init returned InitQueue - Calling pthread_cond_init InitQueue - pthread_cond_init returned winInitMultiWindowWM - Hello winInitMultiWindowWM - Calling pthread_mutex_lock () winMultiWindowXMsgProc - Hello winMultiWindowXMsgProc - Calling pthread_mutex_lock () glWinScreenProbe:1390: glWinScreenProbe fixup_visuals:1303: fixup_visuals init_screen_visuals:1336: init_screen_visuals (--) 5 mouse buttons found (--) Setting autorepeat to delay=500, rate=31 (--) winConfigKeyboard - Layout: "00000804" (00000804) (EE) Keyboardlayout "Chinese (Simplified) - US Keyboard" (00000804) is unknown Could not init font path element D:\Program Files (x86)\Xming/fonts/misc/, removing from list! Could not init font path element D:\Program Files (x86)\Xming/fonts/TTF/, removing from list! Could not init font path element D:\Program Files (x86)\Xming/fonts/Type1/, removing from list! Could not init font path element D:\Program Files (x86)\Xming/fonts/75dpi/, removing from list! Could not init font path element D:\Program Files (x86)\Xming/fonts/100dpi/, removing from list! Could not init font path element C:\Program Files\Xming\fonts\dejavu, removing from list! Could not init font path element C:\Program Files\Xming\fonts\cyrillic, removing from list! Could not init font path element C:\WINDOWS\Fonts, removing from list! winInitMultiWindowWM - pthread_mutex_lock () returned. winInitMultiWindowWM - pthread_mutex_unlock () returned. winInitMultiWindowWM - DISPLAY=127.0.0.1:10.0 winMultiWindowXMsgProc - pthread_mutex_lock () returned. winMultiWindowXMsgProc - pthread_mutex_unlock () returned. winMultiWindowXMsgProc - DISPLAY=127.0.0.1:10.0 winProcEstablishConnection - Hello winInitClipboard () winProcEstablishConnection - winInitClipboard returned. winClipboardProc - Hello DetectUnicodeSupport - Windows Vista winClipboardProc - DISPLAY=127.0.0.1:10.0 winInitMultiWindowWM - XOpenDisplay () returned and successfully opened the display. winMultiWindowXMsgProc - XOpenDisplay () returned and successfully opened the display. winClipboardProc - XOpenDisplay () returned and successfully opened the display. 

Here is my sshd_config on VPS:

 # $OpenBSD: sshd_config,v 1.80 2008/07/02 02:24:18 djm Exp $ # This is the sshd server system-wide configuration file. See # sshd_config(5) for more information. # This sshd was compiled with PATH=/usr/local/bin:/bin:/usr/bin # The strategy used for options in the default sshd_config shipped with # OpenSSH is to specify options with their default value where # possible, but leave them commented. Uncommented options change a # default value. #Port 22 #AddressFamily any #ListenAddress 0.0.0.0 #ListenAddress :: # Disable legacy (protocol version 1) support in the server for new # installations. In future the default will change to require explicit # activation of protocol 1 Protocol 2 # HostKey for protocol version 1 #HostKey /etc/ssh/ssh_host_key # HostKeys for protocol version 2 #HostKey /etc/ssh/ssh_host_rsa_key #HostKey /etc/ssh/ssh_host_dsa_key # Lifetime and size of ephemeral version 1 server key #KeyRegenerationInterval 1h #ServerKeyBits 1024 # Logging # obsoletes QuietMode and FascistLogging #SyslogFacility AUTH SyslogFacility AUTHPRIV #LogLevel INFO # Authentication: #LoginGraceTime 2m #PermitRootLogin yes #StrictModes yes #MaxAuthTries 6 #MaxSessions 10 #RSAAuthentication yes #PubkeyAuthentication yes #AuthorizedKeysFile .ssh/authorized_keys #AuthorizedKeysCommand none #AuthorizedKeysCommandRunAs nobody # For this to work you will also need host keys in /etc/ssh/ssh_known_hosts #RhostsRSAAuthentication no # similar for protocol version 2 #HostbasedAuthentication no # Change to yes if you don't trust ~/.ssh/known_hosts for # RhostsRSAAuthentication and HostbasedAuthentication #IgnoreUserKnownHosts no # Don't read the user ~/.rhosts and ~/.shosts files #IgnoreRhosts yes # To disable tunneled clear text passwords, change to no here! #PasswordAuthentication yes #PermitEmptyPasswords no PasswordAuthentication yes # Change to no to disable s/key passwords #ChallengeResponseAuthentication yes ChallengeResponseAuthentication no # Kerberos options #KerberosAuthentication no #KerberosOrLocalPasswd yes #KerberosTicketCleanup yes #KerberosGetAFSToken no #KerberosUseKuserok yes # GSSAPI options #GSSAPIAuthentication no GSSAPIAuthentication yes #GSSAPICleanupCredentials yes GSSAPICleanupCredentials yes #GSSAPIStrictAcceptorCheck yes #GSSAPIKeyExchange no # Set this to 'yes' to enable PAM authentication, account processing, # and session processing. If this is enabled, PAM authentication will # be allowed through the ChallengeResponseAuthentication and # PasswordAuthentication. Depending on your PAM configuration, # PAM authentication via ChallengeResponseAuthentication may bypass # the setting of "PermitRootLogin without-password". # If you just want the PAM account and session checks to run without # PAM authentication, then enable this but set PasswordAuthentication # and ChallengeResponseAuthentication to 'no'. #UsePAM no UsePAM yes # Accept locale-related environment variables AcceptEnv LANG LC_CTYPE LC_NUMERIC LC_TIME LC_COLLATE LC_MONETARY LC_MESSAGES AcceptEnv LC_PAPER LC_NAME LC_ADDRESS LC_TELEPHONE LC_MEASUREMENT AcceptEnv LC_IDENTIFICATION LC_ALL LANGUAGE AcceptEnv XMODIFIERS #AllowAgentForwarding yes #AllowTcpForwarding yes GatewayPorts yes #X11Forwarding no X11Forwarding yes #X11DisplayOffset 10 X11UseLocalhost yes #PrintMotd yes #PrintLastLog yes #TCPKeepAlive yes #UseLogin no #UsePrivilegeSeparation yes #PermitUserEnvironment no #Compression delayed #ClientAliveInterval 0 #ClientAliveCountMax 3 #ShowPatchLevel no #UseDNS yes #PidFile /var/run/sshd.pid #MaxStartups 10:30:100 #PermitTunnel no #ChrootDirectory none # no default banner path #Banner none # override default of no subsystems Subsystem sftp /usr/libexec/openssh/sftp-server # Example of overriding settings on a per-user basis #Match User anoncvs # X11Forwarding no # AllowTcpForwarding no # ForceCommand cvs server 

And I turned on X11 forwarding

What causes the error above?

---

New Additional Information

According to @lilydjwg's answer, I filled in “display location X” and then tried again, but it is still wrong:

 Using username "root". Authenticating with public key "rsa-key-20150906" from agent Last login: Thu Jan 21 22:24:57 2016 from 222.222.150.82 [ root@mairo ~]# echo $DISPLAY localhost:10.0 [ root@mairo ~]# gedit process 6968: D-Bus library appears to be incorrectly set up; failed to read machine uuid: Failed to open"/var/lib/dbus/machine-id": No such file or directory See the manual page for dbus-uuidgen to correct this issue. D-Bus not built with -rdynamic so unable to print a backtrace Aborted [ root@mairo ~]# 

Answer 1

PuTTY cannot find your X server because you did not say this. (Linux ssh does not have this problem because it runs under X, so it just uses this.) Fill in the blank field after the "X display location" with the address of your Xming server.

Or try MobaXterm . It has an integrated X server.

Answer 2

Other answers are outdated or incomplete, or simply do not work.

You also need to specify the X-11 server on the host computer to run the GUId programs. If the client is a Windows machine, install Xming. If the client is a Linux machine, install XQuartz.

Now suppose this is a Windows connection to Linux. To be able to run X11 programs on top of putty, do the following:

 - Launch XMing on Windows client - Launch Putty * Fill in basic options as you know in session category * Connection -> SSH -> X11 -> Enable X11 forwarding -> X display location = :0.0 -> MIT-Magic-Cookie-1 -> X authority file for local display = point to the Xming.exe executable 

Of course, the ssh server had to allow desktop sharing "Allow another user to view your desktop."

MobaXterm and other complete remote desktop programs also work.

Answer 3

A D-Bus error can be resolved using a dbus start:

 dbus-launch command 

Answer 4

Do not log in as root, try another with sudo permissions.

Answer 5

you should install x server such as XMing. and keep server x running. configure your putty like this: Connection-Data-SSH-X11-Enable Forwarding X11 should be checked. and X display location: localhost: 0