Test dns resolver

test.js

const dns = require('dns');
let i = 1;
let errors = 0;
let l = setInterval(()=>{
  const ip = `${Math.floor((Math.random() * 254) + 1)}.${Math.floor((Math.random() * 254) + 1)}.${Math.floor((Math.random() * 254) + 1)}.${Math.floor((Math.random() * 254) + 1)}`;
  dns.resolve4(`${ip}.nip.io`, (err, result) => {
       if (err) {
         errors += 1;
         process.stdout.write('!');
       } else {
       process.stdout.write('.');
      }
  });
  i += 1;
  if (i>100) {
    clearInterval(l);
    console.log(`\nErrors:${errors}`)
    process.exit(0);  
  }
  
}, 3000);