TightVNC "Failed to connect to server" issue

[Sergio]

I have just set up TightVNC on my home machine which is running XP Home
edition. It is my first experience using VNC with port forwarding from
a router (I have comcast for internet access and a SpeedStream 2623
wireless router connecting my cable modem to my PC). When I try to
establish a connection from a client, it will pause for maybe 10
seconds and then return with a "Failed to connect to server" dialog.
The puzzling thing is that I turned on logging for the server and from
the log file it looks like it's connecting just fine. The log entry
looks like this:

Tue Feb 08 22:17:17 2005
vncSockConnect.cpp : accepted connection from xx.xx.xx.x
vncClient.cpp : client connected : xx.xx.xx.xx (id 1)

If I use http://www.gotomyvnc.com/ it tells me that my VNC server is
accepting connections just fine (and that entry too shows up in the log

Could anybody give me some guidance as to why the log shows that the
client connects, but the client doesn't seem to realize this?

I'm a bit suspicious of the advanced settings in the tightvnc server,
which I admittedly don't fully understand. I have:
For Query Settings:
Query Console on incoming connections: Checked
Query Timeout: 120
Default Action: Accept
Allow option to accept without authentication: not checked
For Administration:
Disable empty passwords: checked
Allow loopback connections: not checked

If anybody has any clue whatsoever what I can try, I would very much
appreciated. So far all my spelunking in documentation and FAQ's have
not turned out anything that works

Thanks!

Sergio.

 

[Guest]

Sergio:
Here's a few things to check:

When you set up the Server on your PC, you had to specify a port, possibly
5900. This port wil need to be opened on your router. This can be done in
the port forwarding section. You want to forward whatever port you specified
during setup to your PC's internal IP address on the network utilizing a
TCP/IP connection (opposed to UDP) (the internal network IP is probably
something like 192.168.1.xxx). If you don't know your IP, go to Start--> Run
and type CMD and hit enter. Then type ipconfig /all at the prompt and scroll
down to find your IP address.

Also, uncheck the box for query console on incoming connection. What this
means is that the PC you are trying to connect to is waiting at a pop-up box
for someone to click OK to accept the incoming VNC request. If no one is
sitting at the computer you want to control, you will get the timeout message
you have been getting.

Also make sure you are specifying a password that must be entered in order
to access the PC. This will ensure security for the connection, and will
have no affect on the issues you have been having.

Good luck, I hope this helps. Let me know either way. If it doesn't, I'll
see what other advice I can offer.

-Jon

 

[Sergio]

Jon: Thanks very much for your reply. I think that I have all the
settings indicated by you in order (port forwarding and such). I assume
this is the case given that gotomyvnc checks out fine. Just in case it
was a firewall issue, I retried the whole thing turning off my router
firewall and my winXP SP2 firewall too and still no dice... Do you
happen to know what the "Allow Loopback Connections" setting is for?
That's still a mystery to me... In the meantime, I will try it from a
couple of different clients just to make sure it's not a client
problem.

Thanks again for your advice!

Sergio.

 

[Guest]

Sergio,

The 'Allow Local Loopback Connection' is not needed. It is used for secure
tunneling (like SSH) because the actual connection is done from the SSH
server over the loopback address. This is used for tunneling within your
network. Since you are trying to access from the outside and probably will
have no need for SSH tunneling, this feature does not need to be enabled.

Did you have any luck trying from a different client?

-Jon

 

[Sergio]

Hello again! Indeed, it turned out to be some client-specific issue. I
was able to connect from a different PC and it's now working just fine.

Thanks again for all your help!

Sergio.