The MQTT protocol Client ID cannot be longer than 23 characters (MQTTEXCEPTION:MQISDP ClientId > x bytes)

Encounter an MQTT problem today, MQTTEXCEPTION:MQISDP ClientId > bytes

The ClientID is longer than 23 o'clock and cannot be linked to an MQTT server.

After viewing protocol discovery:Client Identifier (Client ID) is between1and the ata unique identifier for the client-to-server character length. It must be in the search for a client to connect to a server is unique, is in the processingQoSlevel1and the2the messageIDin the key. If the clientIDinclude atcharacters, server responseCONNECTmessage, through aCONNACK, return code2: The identifier was rejected.

This is described in the English original agreement:

e No, it seems that the beginning version has a 23-character limit, and later versions can be more than 23 characters.

However, the latest Mosquitto only support to 3.1.1, helpless can only change the rules of ClientID, not more than 23 characters.

The MQTT protocol Client ID cannot be longer than 23 characters (MQTTEXCEPTION:MQISDP ClientId > x bytes)