Test your knowledge

1. Which of the following can we use to secure and encrypt communications between the MQTT clients and the MQTT server?

   1. TLS.

   2. TCP.

   3. HTTPS.

2. Which is the default port number for MQTT over TLS?

   1. 1883.

   2. 9883.

   3. 8883.

3. If we specify true as the value for the require_certificate option of the Mosquitto configuration file:

   1. Clients that want to connect to the MQTT server will require a client certificate.

   2. Clients that want to connect to the MQTT server won't require a client certificate.

   3. Clients that want to connect to the MQTT server can provide an optional client certificate.

4. Which of the following utilities allows us to generate an X.509 digital certificate?

   1. OpenX509.

   2. OpenSSL.

   3. TLS4You.

5. When we use MQTT over TLS:

   1. There is just a small bandwidth overhead but no processing overhead at all compared with MQTT over TCP without TLS.

   2. There are both bandwidth and processing overheads compared with MQTT over TCP without TLS.

   3. There is no overhead compared with MQTT over TCP without TLS.