vnc-server installed and running but not visible over the network

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Unable to connect on LAN using VNCViewer to a TigerVNC-Server on Centos

My Centos 6 installation of Vino or more accurately tigervnc-server is set up and starts successfully as defined by the procedure here:

http://wiki.centos.org/HowTos/VNC-Server

I am however unable to connect to the server using the vnc-client on a W7 machine or using a java enabled browser.

I have configured a user, namely '1:mark'

After running "ss -l" to determine the port (thanks to arcyqwerty for the netstat suggestion), I determined the correct port is 5901 or 5902.

ss -l output

State      Recv-Q Send-Q     Local Address:Port       Peer Address:Port   
LISTEN     0      50                     *:mysql                 *:*       
LISTEN     0      5                     :::vnc-server           :::*       
LISTEN     0      5                      *:5901                  *:*       
LISTEN     0      128                   :::41485                :::*       
LISTEN     0      5                     :::5902                 :::*

Below is the output of my /home/mark/.vnc/log after service start

Thu Dec  5 12:09:58 2013
vncext:      VNC extension running!
vncext:      Listening for VNC connections on all interface(s), port 5901
vncext:      created VNC server for screen 0
GNOME_KEYRING_SOCKET=/tmp/keyring-icjZAi/socket
SSH_AUTH_SOCK=/tmp/keyring-icjZAi/socket.ssh
GNOME_KEYRING_PID=7644
Failed to play sound: File or data not found
An instance of nm-applet is already running.
** Message: adding killswitch idx 2 state KILLSWITCH_STATE_SOFT_BLOCKED
** Message: killswitch 2 is KILLSWITCH_STATE_SOFT_BLOCKED
** Message: killswitches state KILLSWITCH_STATE_SOFT_BLOCKED
05/12/2013 12:10:02 PM Autoprobing TCP port in (all) network interface
05/12/2013 12:10:02 PM Listening IPv{4,6}://*:5900
05/12/2013 12:10:02 PM Listening IPv4://0.0.0.0:5900
05/12/2013 12:10:02 PM Problems in NewSocketListenTCP(), sock=-1
05/12/2013 12:10:02 PM Listening IPv{4,6}://*:5901
05/12/2013 12:10:02 PM Listening IPv4://0.0.0.0:5901
05/12/2013 12:10:02 PM Problems in NewSocketListenTCP(), sock=-1
05/12/2013 12:10:02 PM Listening IPv{4,6}://*:5902
05/12/2013 12:10:02 PM Autoprobing selected port 5902
05/12/2013 12:10:02 PM Advertising authentication type: 'VNC Authentication' (2)
05/12/2013 12:10:02 PM Advertising security type: 'VNC Authentication' (2)
** Message: killswitch 2 is KILLSWITCH_STATE_SOFT_BLOCKED
** Message: killswitches state KILLSWITCH_STATE_SOFT_BLOCKED

(polkit-gnome-authentication-agent-1:7711): GLib-GObject-WARNING **: cannot register     
existing type `_PolkitError'

(polkit-gnome-authentication-agent-1:7711): GLib-CRITICAL **: g_once_init_leave: assertion `initialization_value != 0' failed
Initializing nautilus-gdu extension
Initializing nautilus-open-terminal extension
(null):  Warning no default label for /home/mark/.gvfs`

My /etc/sysconfig/vncservers contains

VNCSERVERS="1:mark"
VNCSERVERARGS[1]="-geometry 800x600"

However from the netstat it appears that ports 5900, 5901 and 5902 are involved. Here are the results of my tests:

  1. browsed on the host using 'localhost:5900' Result: RFB 003.007
  2. browsed on the host using 'localhost:5901' Result: RFB 003.008. (note: user:mark)
  3. browsed on the host using 'localhost:5902' Result: RFB 003.007
  4. VNC'd on the host using 'localhost:5901' Result: worked.

Note: From http://www.realvnc.com/docs/rfbproto.pdf RFB represents the Remote Frame Buffer required protocol version numbers.

I tried 1,2,3 and 4 from above substituting localhost:port for the 'hosts ip':port on a network client machine and all timed-out.

The following extra steps have been taken

  • Turned off the firewall
  • Temporarily disabled SeLinux
  • Successfully pinged host from client on LAN.

I am also successfully running a visible httpd service from the offending host

Any pointers would be appreciated.

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arcyqwerty On BEST ANSWER

Make sure that the server is actually runnning (try ps or ps aux).

If that works, then try netstat to make sure it's LISTEN on the right port