Chapter 4: Setting Up a Lab Environment

1. To publish an MQTT message with a Hello payload to the /test topic, you have to run mosquitto_pub -t "/test" -m "Hello!" in the Terminal.
2. To subscribe to MQTT messages that are sent to the /test channel, you have to run mosquitto_sub -t "/test" in the Terminal.
3. The -t command-line flag stands for topic.
4. The -m command-line flag stands for message.
5. This is an exploratory exercise. Go to https://shiftr.io/explore and have a look around.
6. This is an exploratory exercise.

7. This is an exploratory exercise. If you are having problems, note that, in the hands-on chapters, we will make use of third-party apps to send and receive MQTT messages together.