MQTT broker setup (Mosquitto) in Raspberry Pi - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is Mosquitto in the context of MQTT?

Mosquitto is a lightweight MQTT broker that manages message exchange between devices using the MQTT protocol.

beginner

Which command installs Mosquitto on a Raspberry Pi running Raspberry Pi OS?

Use sudo apt update followed by sudo apt install mosquitto mosquitto-clients to install Mosquitto and its clients.

beginner

How do you start the Mosquitto service and enable it to run on boot?

Run sudo systemctl start mosquitto to start and sudo systemctl enable mosquitto to enable it at boot.

beginner

What is the default port Mosquitto listens on for MQTT connections?

Mosquitto listens on port 1883 by default for MQTT client connections.

beginner

How can you test if Mosquitto broker is working on your Raspberry Pi?

Use mosquitto_sub -h localhost -t test/topic in one terminal to subscribe, and mosquitto_pub -h localhost -t test/topic -m "Hello" in another to publish a message. If the subscriber shows the message, the broker works.

Which command installs Mosquitto on Raspberry Pi?

A sudo install mosquitto

B sudo apt-get remove mosquitto

C sudo apt install mosquitto mosquitto-clients

D sudo systemctl start mosquitto

The correct command to install Mosquitto and its clients is 'sudo apt install mosquitto mosquitto-clients'.

What port does Mosquitto use by default for MQTT?

A 8080

B 1883

C 443

D 22

Mosquitto listens on port 1883 by default for MQTT connections.

How do you enable Mosquitto to start automatically on boot?

A sudo mosquitto start

B sudo systemctl disable mosquitto

C sudo apt install mosquitto

D sudo systemctl enable mosquitto

Use 'sudo systemctl enable mosquitto' to enable Mosquitto service at boot.

Which command subscribes to a topic 'test/topic' on local Mosquitto broker?

A mosquitto_sub -h localhost -t test/topic

B mosquitto_pub -h localhost -t test/topic

C mosquitto_start -t test/topic

D mosquitto_listen -t test/topic

The 'mosquitto_sub' command subscribes to a topic; here it listens to 'test/topic'.

What is the role of Mosquitto in MQTT communication?

A It is a broker managing message delivery between clients.

B It is a database for storing MQTT messages.

C It encrypts MQTT messages.

D It acts as a client sending messages.

Mosquitto acts as a broker that manages message delivery between MQTT clients.

Explain the steps to install and start Mosquitto broker on a Raspberry Pi.

Think about commands using apt and systemctl.

Describe how to test if your Mosquitto broker is working correctly on your Raspberry Pi.

Use two terminal windows for testing publish and subscribe.