眾所周知，UDP數據傳輸方式有 單播，組播，廣播。
其中單播模式是最常用，這里就不再啰嗦了，網上隨便都能搜到。

下面的示例主要實現簡單的UDP組播方式?？梢哉Ｊ瞻l(fā)UDP數據。

Server端代碼

const dgram = require('dgram');
const server = dgram.createSocket('udp4');

// const local_ip = "192.168.0.xx";
const multicast_ip = "225.0.0.100";  // 這里必須是一個組播地址(D類IP地址)

server.on('close', ()=>{
    console.log('close socket');
});

server.on('listening', ()=>{
    console.log('listening...');
    server.setBroadcast(true);
    server.setMulticastTTL(128);
    server.addMembership(multicast_ip);

    setInterval(()=>{
        send_msg();
    }, 2000);
});

server.on('message', (msg, rinfo)=>{
    console.log(`receive client message from ${rinfo.address}: ${rinfo.port}: ${msg}`);
});

server.bind();  // 隨機綁定本機一個端口

function send_msg(){
    console.log('send msg');
    server.send('hi, im server...', '8062', multicast_ip);
}

Client端代碼:

const dgram = require('dgram');
var client = dgram.createSocket('udp4');

// const local_ip = '192.168.0.xx';
const multicast_ip = "225.0.0.100";   // 這里必須是一個組播地址(D類IP地址)

client.on('close', ()=>{
    console.log('client closed');
});

client.on('error', (err) =>{
    console.log('client error' + err);
});

client.on('listening', ()=>{
    console.log('client listening...');
    client.setBroadcast(true);
    client.setMulticastTTL(128);
    client.addMembership(multicast_ip);
});

client.on('message', (msg, rinfo) => {
    console.log(`receive server message from ${rinfo.address}: ${rinfo.port}: ${msg}`);
});
client.bind('8062');  // 監(jiān)聽組播數據的端口

參考:

• https://www.daozhao.com/8277.html
• https://stackoverflow.com/questions/14130560/nodejs-udp-multicast-how-to