Check response for RDP services

[Anon Anon]

I have a remote hub I am having some issues with in that I stop getting data back from it due to an OS issue (yet to be determined). Up until now I have used net_connect to effectively 'ping' the IP of this remote hub on a number of different ports to ensure its availability. However, when I get this OS error I am still able to communicate using net_connect but the server is not able to respond as it has bluescreened. So I do not get an alarm for loss of communication. One thing I have noticed is that I am unable to RDP to this remote hub so my question is as follows,

 

Is there a probe I could use where it could try to connect to the remote hub server using RDP and check for a response to be able to login and get an alarm if I cannot? Maybe the E2E probe?

 

Thank you

[Anon Anon]

To do a simple port test of RDP you could use the net_connect probe on port 3389.

[Anon Anon]

If you need to make sure you get data over a connection rather than just testing the TCP three-way handshake, the net_connect probe supports a challenge-response test. From what I saw when I tested it one time, you can even check for a response without a challenge. The trick is connecting to a port that will work with a challenge-response test. I suspect most ports will not return anything useful (probably needs to be text to work in the probe). I know that SMTP and SSH both spit text at you when you first connect to the port, so those would work. And HTTP usually answers a GET request. If you are not running any services that would work well with a challenge-response test, you could always install a service to use for that purpose alone.

 

You probably could so something useful with E2E, although I think it could be a bit tricky. It might not hurt to try and see how far along you get in a short time.

 

-Keith

[Anon Anon]

Here is a simple little batch file that use the portqry command which is part of the resource kit to check rdp and return some info.

 

:Top
portqry -n <your ip> -e 3389 -p tcp -q
if errorlevel = 2 goto filtered
if errorlevel = 1 goto failed
if errorlevel = 0 goto success
goto end

:filtered
Echo Port is listening or filtered
goto end

:failed
Echo Port is not listening
Goto end

:success
Echo Port is listening
goto end

:end