Now, we will use the Mosquitto command-line tools to test the client authentication configuration.
The following command specifies the certificate authority certificate file, the client certificate, and the client key. You have to replace ca.crt, board001.crt, and board001.key with the full path to these files created in the certificates directory. However, it is a better idea to copy these files to a new directory as if we were working with files that will be only available to the device that wants to establish a connection with Mosquitto. As with previous commands, this command uses the -h option followed by the MQTT server host. In this case, we specify the IPv4 address of the computer that is running the Mosquitto MQTT server: 192.168.1.1. Notice that this value must match the IPv4 or IPv6 address that we specified...