NodeJS UDP组播如何

Question

我正在尝试将UDP多播数据包发送到：230.185.192.108，以便所有订阅者都会收到。有点卡住了。我相信它正确播放，但似乎无法与任何客户进行任何选择。

服务器

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();
server.setBroadcast(true)
server.setMulticastTTL(128);
server.addMembership('230.185.192.108'); 

setInterval(broadcastNew, 3000);

function broadcastNew() {
    var message = new Buffer(news[Math.floor(Math.random()*news.length)]);
    server.send(message, 0, message.length, 8088, "230.185.192.108");
    console.log("Sent " + message + " to the wire...");
    //server.close();
}

客户端

var PORT = 8088;
var HOST = '192.168.0.102';
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('230.185.192.108');
});

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, HOST);

参考资料有关NodeJS数据报的更多信息

• http://nodejs.org/api/dgram.html

Answer 1

<强>更改：

client.addMembership('230.185.192.108');

到

client.addMembership('230.185.192.108',HOST); //Local IP Address

Answer 2

这个答案很老，但在Google的搜索结果中显得很高。 使用Node v4.4.3，服务器示例失败，错误为EBADF。完整的工作代码块如下：

服务器

//Multicast Server sending messages
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 PORT = 41848;
var MCAST_ADDR = "230.185.192.108"; //not your IP and should be a Class D address, see http://www.iana.org/assignments/multicast-addresses/multicast-addresses.xhtml
var dgram = require('dgram'); 
var server = dgram.createSocket("udp4"); 
server.bind(PORT, function(){
    server.setBroadcast(true);
    server.setMulticastTTL(128);
    server.addMembership(MCAST_ADDR);
});

setInterval(broadcastNew, 3000);

function broadcastNew() {
    var message = new Buffer(news[Math.floor(Math.random()*news.length)]);
    server.send(message, 0, message.length, PORT,MCAST_ADDR);
    console.log("Sent " + message + " to the wire...");
}

<强>客户端：

//Multicast Client receiving sent messages
var PORT = 41848;
var MCAST_ADDR = "230.185.192.108"; //same mcast address as Server
var HOST = '192.168.1.9'; //this is your own IP
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(MCAST_ADDR);
});

client.on('message', function (message, remote) {   
    console.log('MCast Msg: From: ' + remote.address + ':' + remote.port +' - ' + message);
});

client.bind(PORT, HOST);

对于像我这样的新手，client.bind(PORT,HOST);是重要的一点。当绑定到HOST=127.0.0.1时，我无法让客户端接收任何内容，但在使用IP地址时工作。同样，HOST如果被排除，那么在使用单个机器进行测试时该示例将无效（客户端将抛出EADDRINUSE错误）