A *working* (on Windows) UDP Multicast client & server with Node.Js v0.10.25 (I spent a *LOT* of time getting EINVAL and I still don't quite know why :/)

gistfile1.txt

For my own sanity ;) Scraped from a variety of places, including: http://stackoverflow.com/questions/14130560/nodejs-udp-multicast-how-to?utm_medium=twitter&utm_source=twitterfeed

!Server

  var news = [
    "Borussia Dortmund wins German championship",
    "Tornado warning for the Bay Area",
    "More rain for the weekend",
    "Android tablets take over the world",
    "iPad2 sold out",
    "Nation's rappers down to last two samples"
  ];

  var dgram = require('dgram'); 
  var server = dgram.createSocket("udp4"); 
  server.bind( function() {
    server.setBroadcast(true)
    server.setMulticastTTL(128);
    setInterval(broadcastNew, 3000);
  });
  
  
  
  function broadcastNew() {
      var message = new Buffer(news[Math.floor(Math.random()*news.length)]);
      server.send(message, 0, message.length, 5007, "224.1.1.1");
      console.log("Sent " + message + " to the wire...");
  }

!Client

  var PORT = 5007 ;
  var dgram = require('dgram');
  var client = dgram.createSocket('udp4');
  
  client.on('listening', function () {
      var address = client.address();
      console.log('UDP Client listening on ' + address.address + ":" + address.port);
      client.setBroadcast(true)
      client.setMulticastTTL(128); 
      client.addMembership('224.1.1.1');
  });
  
  client.on('message', function (message, remote) {   
      console.log('A: Epic Command Received. Preparing Relay.');
      console.log('B: From: ' + remote.address + ':' + remote.port +' - ' + message);
  });
  
  client.bind(PORT);

I've been trying to do this for days! This is the first working model I've seen. Thank you!!!

EINVAL indicates that the socket already has an address (see http://www.cs.utah.edu/dept/old/texinfo/glibc-manual-0.02/library_15.html). Maybe you tried to bind twice?

Thank you for this but how can the client send data back to the server?

still works right out of the box! Thank you!

The only things I changed was

• var client = dgram.createSocket({ type: 'udp4', reuseAddr: true }) in the client and
• var message = new Buffer.from(news[Math.floor(Math.random() * news.length)]) in the server.