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I am trying to setup an iot-edge device as an edge gateway. We wouldn't want our leaf/sensor/downstream devices directly connecting to the internet/cloud, and thus I would expect the iot-edge-gateway(as it name suggests) to bridge the connection between downstream devices and the cloud/iot-hub. However, I realize that the connection string for iot-hub/edge at any device level is simply

connection-string-for-iothub-with-gatewayhostwayAppended

This makes me assume that downstream devices transmit messages to an endpoint (prolly messages/* )to cloud/iot-hub and it is from there that gateway gets it(works with that data maybe then) and forwards it back to the $upstream, which shuns the whole point of a gateway.

Here in the message routing section of IOT-EDGE-GATEWAY https://docs.microsoft.com/en-us/azure/iot-edge/how-to-create-transparent-gateway, in the ROUTE MESSAGES FROM DOWNSTREAM DEVICES section

{
    "routes":{
        "sensorToAIInsightsInput1":"FROM /messages/* WHERE NOT IS_DEFINED($connectionModuleId) INTO BrokeredEndpoint(\"/modules/ai_insights/inputs/input1\")", 
        "AIInsightsToIoTHub":"FROM /messages/modules/ai_insights/outputs/output1 INTO $upstream" 
    } 
}

makes it sound like the gateway is routing messages falling on the built-in-endpoint(Default) to $upstream. I can't find any other clearer documentations over the web on this subject. I would really appreciate if someone clears this up. I was expecting the connection string for edge-gateway(that i'd mention in the device end to be something along the lines of localhost:port and not cloudaddress+gatewayhostname)

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如果您的连接字符串包含网关主机名 - 并且您在设备上使用的 SDK 可以正确处理此问题，则设备仅连接到网关，而不连接到 IoT 中心。

您可以在此处查看 .NET SDK 中的示例：

this.HostName = builder.GatewayHostName == null || builder.GatewayHostName == "" ? builder.HostName : builder.GatewayHostName;

https://github.com/Azure/azure-iot-sdk-csharp/blob/f86cb76470326f5af8426f3c2695279f51f6e0c8/iothub/device/src/IotHubConnectionString.cs#L30

如果设置了网关主机名，它实际上会覆盖连接的 IoT 中心主机名。

于 2019-07-12T07:24:57.873 回答