Listeners
The network ports that mosquitto listens on can be controlled using listeners. The default listener options can be overridden and further listeners can be created.
General Options
bind_address address
Listen for incoming network connections on the specified IP address/hostname only. This is useful to restrict access to certain network interfaces. To restrict access to mosquitto to the local host only, use "bind_address localhost". This only applies to the default listener. Use the listener variable to control other listeners.
Not reloaded on reload signal.
http_dir directory
When a listener is using the websockets protocol, it is possible to serve http data as well. Set http_dir to a directory which contains the files you wish to serve. If this option is not specified, then no normal http connections will be possible.
Not reloaded on reload signal.
listener port
Listen for incoming network connection on the specified port. A second optional argument allows the listener to be bound to a specific ip address/hostname. If this variable is used and neither bind_address nor port are used then the default listener will not be started. This option may be specified multiple times. See also the mount_point option.
Not reloaded on reload signal.
max_connections count
Limit the total number of clients connected for the current listener. Set to -1 to have "unlimited" connections. Note that other limits may be imposed that are outside the control of mosquitto. See e.g. limits.conf(5).
Not reloaded on reload signal.
mount_point topic prefix
This option is used with the listener option to isolate groups of clients. When a client connects to a listener which uses this option, the string argument is attached to the start of all topics for this client. This prefix is removed when any messages are sent to the client. This means a client connected to a listener with mount point example can only see messages that are published in the topic hierarchy example and above.
Not reloaded on reload signal.
port port number
Set the network port for the default listener to listen on. Defaults to 1883.
Not reloaded on reload signal.
protocol value
Set the protocol to accept for this listener. Can be mqtt, the default, or websockets if available.
Websockets support is currently disabled by default at compile time. Certificate based TLS may be used with websockets, except that only the cafile, certfile, keyfile and ciphers options are supported.
Not reloaded on reload signal.
use_username_as_clientid [ true | false ]
Set use_username_as_clientid to true to replace the clientid that a client connected with with its username. This allows authentication to be tied to the clientid, which means that it is possible to prevent one client disconnecting another by using the same clientid. Defaults to false.
If a client connects with no username it will be disconnected as not authorised when this option is set to true. Do not use in conjunction with clientid_prefixes.
See also use_identity_as_username.
Not reloaded on reload signal.
websockets_log_level level
Change the websockets logging level. This is a global option, it is not possible to set per listener. This is an integer that is interpreted by libwebsockets as a bit mask for its lws_log_levels enum. See the libwebsockets documentation for more details.
To use this option, log_type websockets must also be enabled. Defaults to 0.
