- (Exam Topic 3)
You have three Azure IoT hubs named Hub1, Hub2, and Hub3, a Device Provisioning Service instance, and an IoT device named Device1.
Each IoT hub is deployed to a separate Azure region. Device enrollment uses the Lowest latency allocation policy.
The Device Provisioning Service uses the Lowest latency allocation policy. Device1 is auto-provisioned to
Hub1 by using the Device Provisioning Service. Device1 regularly moves between regions.
You need to ensure that Device1 always connects to the IoT hub that has the lowest latency. What should you do?
Correct Answer:
D
Automated re-provisioning support.
Microsoft added first-class support for device re-provisioning which allows devices to be reassigned to a different IoT solution sometime after the initial solution assignment. Re-provisioning support is available in two options:
Factory reset, in which the device twin data for the new IoT hub is populated from the enrollment list instead of the old IoT hub. This is common for factory reset scenarios as well as leased device scenarios. Migration, in which device twin data is moved from the old IoT hub to the new IoT hub. This is common for scenarios in which a device is moving between geographies.
Reference:
https://azure.microsoft.com/en-us/blog/new-year-newly-available-iot-hub-device-provisioning-service-features/
- (Exam Topic 3)
You have an Azure IoT solution that includes an Azure IoT Hub named Hub1 and an Azure IoT Edge device named Edge1. Edge1 connects to Hub1.
You need to deploy a temperature module to Edge1. What should you do?
Correct Answer:
D
You deploy modules to your device by applying the deployment manifest that you configured with the module information.
Change directories into the folder where your deployment manifest is saved. If you used one of the VS Code IoT Edge templates, use the deployment.json file in the config folder of your solution directory and not the deployment.template.json file.
Use the following command to apply the configuration to an IoT Edge device:
az iot edge set-modules --device-id [device id] --hub-name [hub name] --content [file path] Reference: https://docs.microsoft.com/en-us/azure/iot-edge/how-to-deploy-modules-cli
- (Exam Topic 3)
You are troubleshooting an Azure IoT hub.
You discover that some telemetry messages are dropped before they reach downstream processing. You suspect that IoT Hub throttling is the root cause.
Which log in the Diagnostics settings of the IoT hub should you use to capture the throttling error events?
Correct Answer:
B
The device telemetry category tracks errors that occur at the IoT hub and are related to the telemetry pipeline. This category includes errors that occur when sending telemetry events (such as throttling) and receiving telemetry events (such as unauthorized reader). This category cannot catch errors caused by code running on the device itself.
Note: The metric d2c.telemetry.ingress.sendThrottle is the number of throttling errors due to device throughput throttles.
Reference:
https://docs.microsoft.com/en-us/azure/iot-hub/iot-hub-monitor-resource-health
- (Exam Topic 3)
You have an Azure IoT hub.
You plan to deploy 1,000 IoT devices by using automatic device management. The device twin is shown below.
You need to configure automatic device management for the deployment.
Which target Condition and Device Twin Path should you use? To answer, select the appropriate options in the answer area.
NOTE: Each correct selection is worth one point.
Solution:
Box 1: tags.engine.warpDriveType='VM105a'
Use tags to target twins. Before you create a configuration, you must specify which devices or modules you want to affect. Azure IoT Hub identifies devices and using tags in the device twin, and identifies modules using tags in the module twin.
Box 2: properties.desired.warpOperating
The twin path, which is the path to the JSON section within the twin desired properties that will be set. For example, you could set the twin path to properties.desired.chiller-water and then provide the following
JSON content:
{
"temperature": 66,
"pressure": 28
}
Reference:
https://docs.microsoft.com/en-us/azure/iot-hub/iot-hub-automatic-device-management
Does this meet the goal?
Correct Answer:
A
- (Exam Topic 3)
You have an Azure IoT hub that uses a Device Provisioning Service instance.
You have 1,000 legacy IoT devices that only support MAC address or serial number identities. The device do NOT have a security feature that can be used to securely identify the device or a hardware security module (HSM).
You plan to deploy the devices to a secure environment.
You need to configure the Device Provisioning Service instance to ensure that all the devices are identified securely before they receive updates.
Which attestation mechanism should you choose?
Correct Answer:
B
A common problem with many legacy devices is that they often have an identity that is composed of a single piece of information. This identity information is usually a MAC address or a serial number. Legacy devices may not have a certificate, TPM, or any other security feature that can be used to securely identify the device. The Device Provisioning Service for IoT hub includes symmetric key attestation. Symmetric key attestation can be used to identify a device based off information like the MAC address or a serial number.
Reference:
https://docs.microsoft.com/bs-latn-ba/azure/iot-dps/how-to-legacy-device-symm-key
