node: multicast example

gistfile1.js

var dgram = require('dgram');
var socket = dgram.createSocket('udp4');

var testMessage = "[hello world] pid: " + process.pid;
var multicastAddress = '239.1.2.3';
var multicastPort = 5554;

socket.bind(multicastPort, '0.0.0.0');
socket.addMembership(multicastAddress);

socket.on("message", function ( data, rinfo ) {
  console.log("Message received from ", rinfo.address, " : ", data.toString());
});

setInterval(function () {
  socket.send(new Buffer(testMessage),
      0,
      testMessage.length,
      multicastPort,
      multicastAddress,
      function (err) {
        if (err) console.log(err);

        console.log("Message sent");
      }
  );
}, 1000);

node:events:491
      throw er; // Unhandled 'error' event
      ^

Error: bind EINVAL 0.0.0.0:5554
    at node:dgram:351:20
    at process.processTicksAndRejections (node:internal/process/task_queues:83:21)
Emitted 'error' event on Socket instance at:
    at node:dgram:353:14
    at process.processTicksAndRejections (node:internal/process/task_queues:83:21) {
  errno: -22,
  code: 'EINVAL',
  syscall: 'bind',
  address: '0.0.0.0',
  port: 5554
}

Node.js v18.6.0

Working:

import dgram from 'node:dgram'
const address = '239.1.2.3'
const port = 5554

let socket = dgram.createSocket({
  type: 'udp4',
  reuseAddr: true // for testing multiple instances on localhost
})

socket.bind(port)

socket.on('message', (msg, remote) => {
  console.log(msg.toString().trim())
})

socket.on("listening", function() {
  this.setBroadcast(true)
  this.setMulticastTTL(128)
  this.addMembership(address)
  console.log('Multicast listening . . . ')
})

setInterval(()=>{
  let message = 'Hi! ' + new Date().getTime()
  socket.send(message, 0, message.length, port, address)
}, 500)