General availability: IoT Hub Service Upgrade

### What’s changing: The architecture of your IoT Hub includes a cluster of front-end message processing servers and software that we call the _IoT Hub gateway_. We are rolling out availability, reliability and security improvements to this gateway between November 2022 and April 2023. ### Potential impact: The gateway upgrade will result in: * A forced disconnect and reconnect for all devices. * New static IP addresses for all IoT hubs. ### Device disconnects: Your devices will disconnect from IoT Hub while we upgrade the gateway nodes. The time it takes for your devices to reconnect depends on: * DNS update propagation: If your devices leverage DNS to resolve your IoT hub’s IP address, it will resolve the new IP address after the DNS updates propagate to the device’s DNS server(s) and any local DNS cache expires. * DPS reprovisioning: Reprovisioning is subject to [DPS limits](https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdocs.microsoft.com%2Fen-us%2Fazure%2Fiot-dps%2Fabout-iot-dps%23quotas-and-limits&data=05%7C01%7CNaman.Mehra%40microsoft.com%7Cfd551cb5160445b396b908dabcf7b36b%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C638030069333199427%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=j35tSzn%2BsH8Q%2B9B3Cn4iawsK1SI00PgsPn4ukiDRZKQ%3D&reserved=0). Follow the recommended best practices to [reprovision devices with DPS](https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdocs.microsoft.com%2Fen-us%2Fazure%2Fiot-dps%2Fhow-to-reprovision%23send-a-provisioning-request-from-the-device&data=05%7C01%7CNaman.Mehra%40microsoft.com%7Cfd551cb5160445b396b908dabcf7b36b%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C638030069333199427%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=SPwjMSo%2FdSOIZwGezwn2ZiJZXg2HSzIOAd0Pm2k%2FLs8%3D&reserved=0). Avoid reprovisioning unless IoT Hub returns an error other than 429 or 5xx. * Device connection retry logic: If your devices leverages the Azure IoT SDKs, they will attempt to reconnect according to their [retry policy](https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdocs.microsoft.com%2Fen-us%2Fazure%2Fiot-hub%2Fiot-hub-reliability-features-in-sdks%23retry-patterns&data=05%7C01%7CNaman.Mehra%40microsoft.com%7Cfd551cb5160445b396b908dabcf7b36b%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C638030069333355690%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=1AsZ5VZOqbc4U5p8Z8TOx9hq447bEsfvIUVwUI1qE5Q%3D&reserved=0). * Device connection throttling: [IoT Hub throttles](https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdocs.microsoft.com%2Fen-us%2Fazure%2Fiot-hub%2Fiot-hub-devguide-quotas-throttling&data=05%7C01%7CNaman.Mehra%40microsoft.com%7Cfd551cb5160445b396b908dabcf7b36b%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C638030069333355690%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=9jEHBs9IhIE%2BGncWQ94%2B2u6EEkv9v08zV0IIh7EPmhs%3D&reserved=0) device connections based on your selected tier. ### Firewall rules and effect: * If you followed our [best practices](https://nam06.safelinks.protection.outlook.com/?url=https%3A%2F%2Fdocs.microsoft.com%2Fen-us%2Fazure%2Fiot-hub%2Fiot-hub-understand-ip-address%23best-practices&data=05%7C01%7CNaman.Mehra%40microsoft.com%7Cfd551cb5160445b396b908dabcf7b36b%7C72f988bf86f141af91ab2d7cd011db47%7C1%7C0%7C638030069333355690%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C3000%7C%7C%7C&sdata=6jh%2FA9JdcnGb7rWYysb2HaDlkcCv3pyZ1y0PffTqN24%3D&reserved=0) to configure your IoT Hub by using Fully Qualified Domain Name (FQDN), then _no action is required_. * If you implemented a range-based approach using IoT Hub service tags, _no action is required._ * If you restrict access based on a specific IP address for your IoT Hub, **_follow our best practices and move away from a static IP address. The IP address of your IoT Hub might change at any time for any reason._** * If you cannot follow our best practices or have questions, contact your Azure IoT or Microsoft contacts. * Azure IoT Hub * Services * [ Azure IoT Hub](https://azure.microsoft.com/en-gb/products/iot-hub/)