Delphi apps won't tether on Windows 10

Question

How do I get Windows 10 or its firewall to allow my Delphi 10.2 tethering app to get access to the internet?

When either the desktop or the mobile app is run on Windows 10, there is no request for permission from the firewall and tethering fails.

In contrast, the Delphi mobile Photowall tethering example runs fine on Android and iPad, tethering with the matching desktop application on Windows 7 and MacOS. On Windows 7 and Macintosh, the firewall asks for permission when the app is run.

Answer 1

The app tethering discovery works by using UDP to broadcast a discovery message across ports 2020-2040.

The default timeout for the manager discovery period is 1500 milliseconds. The default timeout for the profiles discovery is 5000 milliseconds. Make sure that you open up the app tethering ports in your firewall if they are not already open. If your network is busy, you might want to set the discovery timeout longer than 1500 milliseconds (I normally use 3000 milliseconds at work and the default at home).

Answer 2

The Windows 10 machine in question automatically installed McAfee internet. I uninstalled McAfee and the Delphi tethering apps immediately triggered Firewall exception request and then worked properly.

Even though I added the Delphi tethering apps to the Windows firewall exception list, McAfee apparently still blocked the apps. The Delphi apps never raised an error when blocked.