node . js socket . settl()方法

原文:https://www.geeksforgeeks.org/node-js-socket-setttl-method/

socket . settl()方法是 dgram 模块内 Socket 类的内置应用编程接口,用于设置或清除 IP_TTL socket 选项,该选项有助于指定允许数据包通过指定路由器或网关的 IP 跳数。

语法:

const socket.setTTL( ttl )

参数:该方法取整数值,表示允许数据包通过指定路由器或网关的 IP 跳数。

返回值:此方法不返回值。

示例 1: 文件名:index.js

java 描述语言

// Node.js program to demonstrate the
// server.setTTL() method

// Importing dgram module
var dgram = require('dgram');

// Creating and initializing client
// and server socket
var client = dgram.createSocket("udp4");
var server = dgram.createSocket("udp4");
let broadcast_address = 12345;

// Catching the message event
server.on("message", function (msg) {

  // Displaying the client message
  process.stdout.write("UDP String: " + msg + "\n");

  // Exiting process
  process.exit();
})
.bind(broadcast_address, () => {

  // Enable the IP_TTL socket option
  // and specifying the number of IP hopes
  // by using the setTTL() method
  server.setTTL(144);
});

// Client sending message to server
client.send("Hello", 0, 7, broadcast_address, "localhost");

输出:

UDP String: Hello

示例 2: 文件名:index . js

Javascript

// Node.js program to demonstrate the
// server.setTTL() method

// Importing dgram module
var dgram = require('dgram');

// Creating and initializing client
// and server socket
var client = dgram.createSocket("udp4");
var server = dgram.createSocket("udp4");

// Catching the message event
server.on("message", function (msg) {

  // Displaying the client message
  process.stdout.write("UDP String: " + msg + "\n");

  // Exiting process
  process.exit();
});

// Catching the listening event
server.on('listening', () => {
  const address = server.address();
  console.log(`server listening
    ${address.address}:${address.port}`);
});

// Binding server with port address
server.bind(1234, () => {

  // Enable the IP_TTL socket option
  // and specifying the number of IP hopes
  // by using the setTTL() method
  server.setTTL(144);
});

// Client sending message to server
client.send("Hello", 0, 7, 1234, "localhost");

输出:

server listening 0.0.0.0:1234
UDP String: Hello

使用以下命令运行 index.js 文件:

node index.js

参考:T2】https://nodejs . org/dist/latest-v 12 . x/docs/API/dgram . html # dgram _ socket _ settl _ TTL