UWP Developing: Local network protocal stack issue

I’m working on developing a Universal Windows App (Windows 10 IoT) recently. My app includes a UDP server for receiving packages.

The issue I found is:
When the UWP running on local computer, the datagram sent by local console application cannot be received.

Normally, while developing a socket based network application, another application for making and sending test packages should be prepared. The problem is, for testing UWP application, either the tester should be prepared as UWP application, or this tester can only be used on another computer laying on the same network.