MQTT

MQTT (Message Queuing Telemetry Transport) is a lightweight messaging protocol designed for constrained devices and low-bandwidth, high-latency networks. It is commonly used in IoT (Internet of Things) applications to facilitate communication between devices. MQTT operates over TCP/IP and uses a publish/subscribe model to exchange messages.

What is MQTT

MQTT (Message Queuing Telemetry Transport) is a lightweight messaging protocol that was developed by IBM and Eurotech in the late 1990s. It is designed to be simple and efficient, making it ideal for use in constrained environments such as small sensors and mobile devices. MQTT is particularly popular in IoT (Internet of Things) applications, where it enables devices to communicate with each other and with central servers.

The protocol operates over TCP/IP and uses a publish/subscribe model to exchange messages. In this model, devices (clients) can publish messages to a broker, which then distributes the messages to other clients that have subscribed to the relevant topics. This decouples the producers and consumers of data, allowing for more flexible and scalable communication.

MQTT's lightweight nature makes it well-suited for environments with limited bandwidth and high latency. It includes features such as Quality of Service (QoS) levels to ensure reliable message delivery, and it supports persistent sessions to maintain state information across network disruptions. These features make MQTT a robust choice for a wide range of applications, from home automation to industrial monitoring.

MQTT runs on TCP and UDP port 1883 and is official IANA port.

Security risk

If port 1883 is open and the MQTT service is running, it could be vulnerable to unauthorized access and data interception. Attackers could potentially publish or subscribe to topics, leading to data breaches or manipulation of IoT devices. Proper authentication and encryption should be implemented to mitigate these risks.

In our UFW tutorial you can follow instructions how you can configure UFW to close port 1883. Use StackChanges to monitor if the MQTT port is closed and stays closed. StackChanges will send an alert if port 1883 is open again.