udp broadcats client

client.js

var dgram = require("dgram");

var port = 18432,
    multicastIP = "224.3.56.114";

var client = dgram.createSocket('udp4');
client.bind(port, "0.0.0.0");

client.on("listening", function(){
    client.setBroadcast(true);
    client.setMulticastTTL(128);
    client.setMulticastLoopback(true);
    client.addMembership(multicastIP, "0.0.0.0");
});

client.on("message", function(message){
    console.log("MUTLICAST MESSAGE");
    console.log(message.toString());
});

send.js

var dgram = require('dgram');
var message = new Buffer(Date());
var sender = dgram.createSocket("udp4");

var port = 18432,
    multicastIP = "224.3.56.114";

sender.bind();

sender.on("listening", function(){
    sender.setBroadcast(true);
    sender.setMulticastTTL(128);
    sender.setMulticastLoopback(true);
    sender.addMembership(multicastIP, "0.0.0.0");
    sender.send(message, 0, message.length, port, multicastIP, function(err, bytes) {
        sender.close();
    });
});

if there is no udp server running how can I verify it before sending the message?

You can’t, UDP is one way protocol - you send the packet and hope for the best. One option would be to design your own protocol over UDP where both ends exchange confirmation packets or something like that.

but if there is no end-point listening udp client doesn't care? no chance to verify even knowing specific host and port? unfortunately, I'm managing only the client part, and the server is not sending anything before I send the first message to it. Do u think it could be possible to use any TCP library?