NetworkInterface.GetAllNetworkInterfaces() appears to be broken in Unity 5.6.0f3 when built for headless linux.
We run it in a Virtual Box VM.
Could someone test that NetworkInterface.GetAllNetworkInterfaces() , does not pull up any of the adapters, and possibly verify if this is a vm issue or a linux issue in general.
This works perfectly on Windows 7-10. But we run the server on headless linux which uses the same source.