1var http=require('http');
2var url = require('url');
3var ports = [7006, 7007, 7008, 7009];
4var servers = [];
5var s;
6function reqHandler(req, res) {
7        var serPort=req.headers.host.split(":");
8        console.log("PORT:"+serPort[1]);//here i get it using http header.
9}
10ports.forEach(function(port) {
11    s = http.createServer(reqHandler);
12    s.listen(port);
13    servers.push(s);
14});

1var http=require('http');
2var ports = [7006, 7007, 7008, 7009];
3var servers = [];
4var s;
5function reqHandler(req, res) {
6    console.log({
7        remoteAddress: req.socket.remoteAddress,
8        remotePort: req.socket.remotePort,
9        localAddress: req.socket.localAddress,
10        localPort: req.socket.localPort,
11    });
12}
13ports.forEach(function(port) {
14    s = http.createServer(reqHandler);
15    s.listen(port);
16    servers.push(s);
17});

1var express = require('express');
2
3let app1 = express();
4let app2 = express();
5
6app1.listen(3000, () => {
7  console.log("Started server on 3000");
8});
9
10app2.listen(3002, () => {
11  console.log("Started server on 3002");   
12});