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The AWS IoT Message Broker is the central point to securely transmit messages to and from all your devices and applications using the HTTPS and MQTT protocols. Devices connect to IoT Core using something called IoT Core endpoints, which allow control plane and data plane access to the cloud services that AWS provides. Each connected device or client must have a credential to interact with the AWS IoT endpoint. Unfortunately, AWS IoT endpoints resolve to dynamic IP Addresses. This is because they are designed to be able to handle different network load situations. To provide resilience and scale, this single FDQN resolves to a different set of IP addresses.