I have set up vncserver successfully on Cent OS 5 virtual server (for testing purposes) and am attempting to connect using RealVNC or TightVNC. I can easily bring up the :1 and :2 sessions but cannot get the :3 and :4 sessions to work. I always get a connection refused type of message. I have checked the ports 5901 - 5904 and they are actively listening :

netstat -an | grep 590
tcp 0 0 127.0.0.1:5901 0.0.0.0:* LISTEN
tcp 0 0 127.0.0.1:5902 0.0.0.0:* LISTEN
tcp 0 0 127.0.0.1:5903 0.0.0.0:* LISTEN
tcp 0 0 127.0.0.1:5904 0.0.0.0:* LISTEN

I have made sure that the vncserver file in /etc/sysconfig is set up correctly:

# VNCSERVERS="2:myusername"
# VNCSERVERARGS[2]="-geometry 800x600 -nolisten tcp -nohttpd -localhost"
VNCSERVERS="1:larry 2:moe 3:curly 4:steve"
VNCSERVERARGS[1]="-geometry 1024x768 -localhost -AlwaysShared"
VNCSERVERARGS[2]="-geometry 1024x768 -localhost -AlwaysShared"
VNCSERVERARGS[3]="-geometry 1024x768 -localhost -AlwaysShared"
VNCSERVERARGS[4]="-geometry 1024x768 -localhost -AlwaysShared"

I have set the export DISPLAY for all users to their corresponding session:

larry -- DISPLAY=localhost:1
moe -- DISPLAY=localhost:2
curly -- DISPLAY=localhost:3
steve -- DISPLAY=localhost:4

Obviously I am using SSH tunneling. I have set up identical /home/<user>/.vnc/xstartup files:

#!/bin/sh

( while true; do xterm; done ) &
# Uncomment the following two lines for normal desktop:
unset SESSION_MANAGER
exec /etc/X11/xinit/xinitrc

[ -x /etc/vnc/xstartup ] && exec /etc/vnc/xstartup
[ -r $HOME/.Xresources ] && xrdb $HOME/.Xresources
xsetroot -solid grey
vncconfig -iconic &
xterm -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" &
twm &
gnome-session &

The log files at /home/<user>/.vnc/CentOS5.ihs.org:1.log are ugly and too large to copy here. The one thing I noticed in ALL of the log files are the statements "No profile for user 'larry' found" (or moe or curly or steve). But the sessions for larry and moe seem to work just fine.

Any suggestions? I must be missing something simple but I can't seem to find it.

could be a firewall issue. Have you tried disabling 1 or 2 to see if 3 or 4 works then?

I disabled the firewall by simply entering:

service iptables stop

Then tried it again with the same results. (I can disable the firewall safely since everything I am doing is behind our firewall.)

I disable 1 and 2 by:

login as larry (and moe, who are :1 and :2 respectively) and

'vncserver -kill :1' and 'vncserver -kill :2'

When I do that and try to connect with :1 or :2, I get a "connection is closed unexpectedly" type of popup message. When I attempt with :3 or :4, I get "Attempting to connect to host" and "Unable to connect to host: Connection refused (10061)" type of popups with RealVNC.

Any more ideas?

it's not likely that it's a firewall issue if youre using an ssh tunnel and connecting to localhost. Are you forwarding all four ports when you make the tunnel?

Well, with the help of a couple of friends here, I got it figured out. Seems that the PuTTY configuration had to have the last two ports configured for tunnelling (5903, 5904). I thought that I had already set that up but evidently didn't save the configuration. I decided to turn OFF the iptables service (everything is behind our firewall) and forego the need to have the PuTTY session running to make ANY tunnelled connection. I set up the vncserver configuration to omit the -localhost parameter like this (omitting the copious comment lines):

VNCSERVERS="1:larry 2:moe 3:curly 4:steve"
VNCSERVERARGS[1]="-geometry 1024x768 -AlwaysShared"
VNCSERVERARGS[2]="-geometry 1024x768 -AlwaysShared"
VNCSERVERARGS[3]="-geometry 1024x768 -AlwaysShared"
VNCSERVERARGS[4]="-geometry 1024x768 -AlwaysShared"

Now my netstats look like this:

netstat -an | grep 590
tcp 0 0 0.0.0.0:5900 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:5901 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:5902 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:5903 0.0.0.0:* LISTEN
tcp 0 0 0.0.0.0:5904 0.0.0.0:* LISTEN

So I am LISTENING for ANY connection to a given port. Now I can make the RealVNC or TightVNC and it still requires me to enter the user passwords. (I want at least that much protection.)