TightVNC Connection Problem

I have the latest version of TightVNC installed on a workstation.  For some reason, I cannot connect to this machine.  I can connect via RDP just fine.  I have tried uninstalling TightVNC and reinstalling.  Same problem.  TightVNC taskbar icon says it is listening for connections, but I cannot connect.  Tried connecting from multiple workstations. Firewall exceptions for TightVNC are in place.  I have also completely disabled the firewall- still unable to connect.  Machine in question is not "listening" on port 5900 (verified through Test-NetConnection in Powershell).  Tried switching to a different port. Connection problem persists.    Any idea how to resolve this problem?
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Davy ParidaensCommented:
You need to forward the following ports 5800 and 5900 tcpon your router and Firewall.


arkhaminmate11nAuthor Commented:
These machines are on a LAN.  So no router or firewall- just a switch.
What happens if you try to use the computer to connect to itself with VNC?  Don't type the password in, just see if it asks for one.

I'd be most suspicious of the firewall, though your comment about the problem persisting while the firewall was disabled says that should not be the issue.  Are you sure it is disabled for the type of network connection (Public, Private, etc.) that is being used?  I have resorted to permitting the specific port in Windows Firewall in order to get VNC to work.

Can you show the results of your Test-Netconnection?  I tried it on my computer (with VNC server properly working) and I get "False" for TcpTestSucceeded.
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arkhaminmate11nAuthor Commented:
I use GPO to deploy Windows Firewall settings.  All machines that are being controlled by the "Windows Firewall GPO" have no problem with VNC connectivity.  Again, I did go into Windows services and completely disable the Windows firewall.  Problem with VNC connectivity persisted.

Here are the PowerShell results:

First is the problem machine.  Second is a machine that is working.

Windows PowerShell
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PS C:\windows\system32> Test-NetConnection co-ws42 -Port 5900
WARNING: TCP connect to co-ws42:5900 failed

ComputerName           : co-ws42
RemoteAddress          :
RemotePort             : 5900
InterfaceAlias         : Ethernet
SourceAddress          :
PingSucceeded          : True
PingReplyDetails (RTT) : 0 ms
TcpTestSucceeded       : False

PS C:\windows\system32> Test-NetConnection co-ws09 -Port 5900

ComputerName           : co-ws09
RemoteAddress          :
RemotePort             : 5900
InterfaceAlias         : Ethernet
SourceAddress          :
PingSucceeded          : True
PingReplyDetails (RTT) : 1 ms
TcpTestSucceeded       : True

PS C:\windows\system32>
I was in error about Test-NetConnection on my computer.  I have results similar to your "good" one.

Did you try having the machine connect to itself with VNC?  I'm presuming that it will also fail.

Any chance there is some other firewall present?
arkhaminmate11nAuthor Commented:
I cannot test connecting to the machine from the machine as a user is currently using the machine.

No other firewall present.
I am somewhat stumped on this one.

I'd try one other thing.  Disable RDP (and confirm that the computer can no longer be reached by RDP), change the VNC port to 3389, then try to connect to the computer with VNC on 3389.
arkhaminmate11nAuthor Commented:
Thanks.  Will do.
arkhaminmate11nAuthor Commented:
I am not sure why or how, but the problem resolved itself.  Prior to the resolution, all I did was disable the firewall, reboot, found the connection failed again, I then re-enabled the firewall, rebooted, and found the connection worked after this sequence of events.  So maybe something got 'hung' up in the firewall?  Anyway, thanks for the help.
I agree that it was likely something odd with the firewall.  The part that is surprising is that it interfered when the service was stopped.  That it blocked VNC even while it was configured to allow it is not nearly as surprising.

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