To reproduce:

1. Open the project, attached by user (NetworkDiscovery.zip)
2. Open "Main" scene if not open
3. Disable your internet connection
4. In Play mode, press Initialize Broadcast

Expected: broadcast does not initialize if there is no internet connection
Actual: broadcast is initalized without any errors even though there is no internet connection

Reproduced in: 5.5.3p2, 5.6.0f3, 5.6.1f1, 2017.1.0b5