Mqtt.js: Client <unknown> disconnected due to protocol error.

[pavankumarkl]

I am using MQTT and below are options that I am passing to connect

var options = {
keepalive: 10,
clientId: '',
protocolId: 'MQTT',
protocolVersion: 3,
clean: true,
reconnectPeriod: 20000,
connectTimeout: 30 * 1000,
protocol:'mqtt',
rejectUnauthorized: false

}
const client = mqtt.connect('mqtt://192.168.127.13:1883',options); -> my local mosquitto broker

can any one help, why I am getting "Client disconnected due to protocol error."

AB#9368700

[MShokry]

same here Any update?

const us = {
    clientId: 'xiot_' + Math.random().toString(16).substr(2, 8),
    username: mqtt.username,
    password: mqtt.password,
    useSSL: false,
    onSuccess: onAction,
    onFailure: onAction,
    protocolId: 'MQTT',
    protocolVersion: 5,
    rejectUnauthorized: false,
    clean: true,
    reconnectPeriod: 20000,
    connectTimeout: 30 * 1000,
    protocol: 'mqtt',
  };
  let client1 = mqtt1.connect('mqtt://192.168.1.16:1883/',us);

[fabien-lg]

Same here!

[jc-delvalle]

So I had the same issue, new mosquitto server installed on OSX with homebrew and using react-native.

For some reason no native mqtt connection could be made so I used websockets.

You'll need to add to mosquitto.conf bellow #port 1883

listener 1883
protocol mqtt

listener 8883
protocol websockets 

When you start mosquitto it should say:

1583550048: mosquitto version 1.6.8 starting
1583550048: Config loaded from /usr/local/etc/mosquitto/mosquitto.conf.
1583550048: Opening ipv6 listen socket on port 1883.
1583550048: Opening ipv4 listen socket on port 1883.

Then connect using:

const client = mqtt.connect('ws://localhost:8883', options);

Hope this helps someone.

[naanuswaroop]

I was getting the error "Client disconnected due to protocol error" in the below scenario:

1. Mosquitto broker started without specifying any certs (cafile, certfile and keyfile) in the mosquitto config file.
2. Mosquitto client (pub or sub) tries to connect to the above broker using proper certificates.

Fix:
Review the mosquitto.conf file. Specify the proper certificates to be used by the broker for authenticating the clients (sub or pub)

[edocod1]

Just to add a trail of this, you will also encounter a protocol error if you try to use a subscription_identifier that's not between the allowed range 1 ~ 2^28-1

[PaulCorbeau]

same here Any update?

const us = {
    clientId: 'xiot_' + Math.random().toString(16).substr(2, 8),
    username: mqtt.username,
    password: mqtt.password,
    useSSL: false,
    onSuccess: onAction,
    onFailure: onAction,
    protocolId: 'MQTT',
    protocolVersion: 5,
    rejectUnauthorized: false,
    clean: true,
    reconnectPeriod: 20000,
    connectTimeout: 30 * 1000,
    protocol: 'mqtt',
  };
  let client1 = mqtt1.connect('mqtt://192.168.1.16:1883/',us);

Same Issue for me, when I try to use the Websocket solution it works but i'm not in charge of the mosquitto server. I would like to use native MQTT protocol for this.

[bikeidaho]

bump?

[YoDaMa]

seems like a pervasive bug. it might be related to some bugs that have been recently fixed in mqtt-packet. It looks like a new version of mqtt-packet (patch-update) was released today. Can you try and see if you're using it and if the problem persists? The mqtt-packet version is 6.8.1.

[mehai]

Hello! Any updates on this? I seem to have the same issue.

[mehai]

seems like a pervasive bug. it might be related to some bugs that have been recently fixed in mqtt-packet. It looks like a new version of mqtt-packet (patch-update) was released today. Can you try and see if you're using it and if the problem persists? The mqtt-packet version is 6.8.1.

I used the 6.9.0 version when I found the bug.

[SibiAkkash]

So I had the same issue, new mosquitto server installed on OSX with homebrew and using react-native.

For some reason no native mqtt connection could be made so I used websockets.

You'll need to add to mosquitto.conf bellow #port 1883

listener 1883
protocol mqtt

listener 8883
protocol websockets 

When you start mosquitto it should say:

1583550048: mosquitto version 1.6.8 starting
1583550048: Config loaded from /usr/local/etc/mosquitto/mosquitto.conf.
1583550048: Opening ipv6 listen socket on port 1883.
1583550048: Opening ipv4 listen socket on port 1883.

Then connect using:

const client = mqtt.connect('ws://localhost:8883', options);

Hope this helps someone.

Yup, this worked. 🎉🎉