remote desktop services

onlinerack used Ask the Experts™
I have installed RDP gateway on windows server 2019 and went through the configuration. I was unable to disable UDP 3391 transport in RDP Gateway windows server 2019

I tried it on 2 separate windows 2019 servers that used the normal install and no GPOs.

Any idea how to get it to turn off. We do not want to use UDP 3391 due to the port being blocked throughout the enterprise.

It is disabled In windows server 2016 by default. I actually would get the same error if I tried to enable it in windows server 2016. But for the scope of the question, We are trying to disable it in 2019.
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AlexSenior Infrastructure Analyst

Sounds silly, can you launch that with administrative rights, I.E right click, run as admin.

why you need to disable the UDP port?
if UDP connection is not possible, server & client should use TCP.
(without user/admin interaction)


So if UDP is on but the user had the port blocked for that port, it would use only the TCP port?
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If you use wireshark, you see connection is established with TCP first, than the connection try to switch to UDP.
i see the blocked UDP packets at the firewall, but the connection keeps stable.


Thanks guys. It makes sense. That is reassuring.

In this case specifically, I had to disable UDP as it is not allowed through the firewalls from the client side. I did that eventually through the registry. But knowing that it would fail back to TCP is good to know.

@alex, good thought, Running as administrator these days with windows is the same as let's reboot to see if that clears it. MS picked that as a new trend.   I tried it, it did not work. I had some hope...

Thank you all for your contributions.
AlexSenior Infrastructure Analyst

Me too, but unfortunately that's the only thing I can offer since I've never set one of these up.

I'll step down so the other experts can have another look :D


You did good Alex... It really could have been that simple. This seems to be an issue with all windows 2019 out of the box as I ran three different installs.
The issue is now marked as resolved as I did the change through the registry.  Dirk, however, did provide valid info that if UDP is blocked, then it would use the TCP only anyways.

Thank you. :)

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