# Plain MQTT protocol listener 1883 # MQTT over TLS 1.1 listener 8883 tls_version tlsv1.1 cafile /tls/ca_certificate.pem certfile /tls/server_certificate.pem keyfile /tls/server_key.pem # MQTT over TLS 1.2 listener 8884 tls_version tlsv1.2 cafile /tls/ca_certificate.pem certfile /tls/server_certificate.pem keyfile /tls/server_key.pem # TODO(This does not appear to be supported on Ubuntu 18.04. Re-try on 20.04 or next LTS release) # MQTT over TLS 1.3 # # listener 8885 # tls_version tlsv1.3 # cafile /tls/ca_certificate.pem # certfile /tls/server_certificate.pem # keyfile /tls/server_key.pem log_dest syslog log_type error log_type warning log_type notice log_type information log_type debug connection_messages true