I have an Azure IoT Edge server which acts as a transparent gateway for my IoT devices (implemented using the Azure IoT SDK). They have been configured as child devices so they work offline, without any Internet connection. This setup works as expected.
Is it possible to send a direct method invocation from the IoT Edge server directly to one of the child IoT devices, without an Internet connection? I have implemented some code (Node.js using the official Azure IoT Device SDK) which connects to the IoT Hub to perform the method invocation. This works if the IoT Edge server is connected to the Internet. However, if I unplug the Internet, the request will simply time out.
I have tried to use the IoT Hub connection string with and without the GatewayHostName=... parameter. Without success unfortunately.
Is this a supported scenario and if so, how can I perform a method invocation from my IoT Edge server to a child IoT device?
