debug faile to connect to server using portqry

8/12/2019 Debug Faile to Connect to Server Using Portqry

1/14

Debug Failed to connect to server!

Version 2

To many of the first time visitors to the forums, the following screenshot may look all toofamiliar.

There are many causes for this error and unfortunately this is all the information availableto the viewer so it isnt possible for the developers to display a more specific errormessage. Microsoft offers a port query utility that can be used to help isolate e actlywhere the connection is failing. !rom Microsofts site" #$ort%ry.e e is a command&lineutility that you can use to help troubleshoot T'$()$ connectivity issues. $ort%ry.e eruns on *indows 2+++&based computers, on *indows $&based computers, and on*indows -erver 2++ &based computers. The utility reports the port status of T'$ and/0$ ports on a computer that you select.1

Microsoft also offers a front end to the command line utility called $ort%uery/) which)ll be using for debugging. 0ownload $ort%uery/) from Microsoft athttp"((www.microsoft.com(downloads(details.asp familyid34 5565 7&869:&;5:


2/14

Is the UltraVNC Server started and listening on the port youthink it is? Ak, lets start at the beginning on the machine you are trying to access from a remotelocation. /ltraVB' installation procedures are presented athttp"((www.uvnc.com(install(installation.html and )ll be assuming that youve lookedthere first. This question can be answered either by connecting the /ltraVB' Viewer tothe /ltraVB' -erver in Coopback mode or using $ort%uery/).

)f youve successfully connected the /ltraVB' Viewer to the /ltraVB' -erver inCoopback mode you can skip to the ne t question. @owever, since this is a debug

procedure using this tool, start the $ort %uery /ser )nterface by clicking Start Run Browse then navigate to the location of the PortQueryUI.exe e ecutable, select it, clickOpen , and press .

The default Enter destination IP or FQDN to query: is the local machine, 127.0.0.1which is what we want so leave that alone. The default Query Type is Query predefined

service: , but we are only verifying that the /ltraVB' server is running and that itslistening on the port we think so change it to Manua y input !uery ports: , set Ports toquery: to "#00 or the port youve set the server to listen to Dfor the remainder of the

procedure )ll refer to port 5


3/14

The results are displayed in the Query Result: area. ) wont bother e plaining the entiredisplay Drefer to the references if you cant understand itE, but what were looking for isthe $%P port "#00 status. )n this case, )ve shown the results with my /ltraVB' -ervernot started so the results are that it is &'$ (I)$E&I&* . This would also be the result if

my server were listening on a different port.)f &'$ (I)$E&I&* , and you installed the /ltraVB' server as a service, check to seethat it has been started. 'lick Start Run , type services.+sc , and press . )n thelist of services you should see ,&% )erver and its Status should be )tarted and itsStartup Type should be -uto+atic .

)f &'$ (I)$E&I&* , and if you didnt install the /ltraVB' server as a service, ensurethat you manually started it.


4/14

)f &'$ (I)$E&I&* , and the server is running verify that it is listening on the port you

think. 0ouble&click on the servers eyeball icon, , to open the administrative properties. Verify that the Main: port under Inco in! "onnections is set to "#00 or that-uto is selected which will also cause the server to listen on port "#00 .

Ance the /ltraVB' server is running and listening on the port we e pect, rerun the$ort%uery/) query and you should get the following result.


5/14

$%P port "#00 status is (I)$E&I&* after the server is running and set to port 5


6/14

Is connection being blocked by your security software? This is the reason why


7/14

The results are displayed in the Query Result: area. *hat were looking for is the $%Pport "#00 status. )n this case, )ve shown the results with the *indows firewall turnedon without e ceptions on the machine running the server so the results are that it isI($E3E4 . This indicates that $ort%ry did not receive a response from the port.

)f I($E3E4 , then the VB' connection may be being blocked by your securitysoftware. To look at the status of the *indows firewall, click Start Run, typefire5a .cp , and press . )f the firewall is on as shown in the followingscreenshot, you need to create an e ception for the connection.


8/14

'lick E#ceptions $dd Port and add a T'$ e ception for the VB' traffic as shown inthe following screenshot then click O% .


9/14

There are too many different security software choices to cover them all here, but thisshould give you an idea of what you need to do. Ance you allow an e ception for the/ltraVB' traffic, rerun the $ort%uery/) query and you should get the following result.

$%P port "#00 status is (I)$E&I&* after adding port e ception.


10/14

Is connection being blocked by your router? @opefully youve been able to confirm that the connection isnt being blocked by yoursecurity software in the previous section, but if not we should be able to confirm thathere. Move back to the $' youre having trouble accessing remotely. Goull need to

identify your public )$ address assigned by your internet service provider or 0yn0B-host name. Gou can see your public )$ address by visiting http"((whatsmyip.org( , butsince most )-$s assign a dynamic )$ address, ) recommend signing up for a free accountat http"((www.dyndns.com( . This will allow you to create a host name that will resolve toyour dynamic public )$ address.

-tart the $ort %uery /ser )nterface by clicking Start Run Browse then navigate to thelocation of the PortQueryUI.exe e ecutable, select it, click Open , and press .

-ince were communicating over the *9B, we need to change the default Enterdestination IP or FQDN to query: to the public )$ address assigned by your )-$ or0yn0B- host name. The default Query Type is Query predefined service: , but we are

only verifying that router is not preventing the connection so change it to Manua yinput !uery ports: , set Ports to query: to "#00 and leave the Protocol: set to its default$%P then click Query .
http://whatsmyip.org/http://www.dyndns.com/http://whatsmyip.org/http://www.dyndns.com/


11/14

The results are displayed in the Query Result: area. *hat were looking for is the $%Pport "#00 status. )n this case, )ve shown the results without port forwarding port 5


12/14

machine you are trying to access from a remote location. Ance port forwarding is set up properly, rerun the $ort%uery/) query and you should get the following result.

$%P port "#00 status is (I)$E&I&* after adding port forwarding.

Bot all routers allow for a connection using the public )$ address from inside the C9B.9s a result, it is possible that a I($E3E4 response may be received even whenconfigured properly. )f youve followed the $ort!orward instructions carefully and stillreceive the I($E3E4 response, you can also check your port forward setup by usingthe following link" https"((www.grc.com( (portprobe35


13/14

possibility in the last step Dif thats the case, refer to the )f I($E3E4 section under thesecurity software question aboveE. -hields/$J returns a Status of 'PE& when itreceives a response from the port so the router has been properly configured. -hields/$Jreturns a Status of % osed when the port has been forwarded to a $', but the /ltraVB'server software is not currently listening on that $'.


14/14

Is connection being blocked by the firewall or proxy at theremote location? 9t this point were sure that everything is set up properly at home so if you still have

problems connecting, then the only other possibility is something on the network of the$' running the /ltraVB' viewer.)t may be possible to resolve this by modifying the port from the default 5

debug faile to connect to server using portqry

Documents