mongodbに接続したい

##mongodbに接続したい
環境
-centOS6
ドットインストール「Node.js入門」に従ってい学習中

やりたいこと
-仮想サーバとmongoDBを接続したい。
接続後”connected to db”と出力される

##エラー

//terminal
[vagrant@localhost nodejs]$ node mongo.js

/home/vagrant/nodejs/node_modules/mongodb/node_modules/mongodb-core/lib/connection/connection.js:532
  let sslOptions = {
  ^^^
SyntaxError: Unexpected strict mode reserved word
    at Module._compile (module.js:439:25)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)
    at Function.Module._load (module.js:312:12)
    at Module.require (module.js:364:17)
    at require (module.js:380:17)
    at Object.<anonymous> (/home/vagrant/nodejs/node_modules/mongodb/node_modules/mongodb-core/index.js:19:15)
    at Module._compile (module.js:456:26)
    at Object.Module._extensions..js (module.js:474:10)
    at Module.load (module.js:356:32)

//mongo.js
var MongoClient = require('mongodb').MongoClient,
    settings = require('./settings');
MongoClient.connect("mongodb://"+settings.host+"/"+settings.db, function(err, db) {
    if (err) { return console.dir(err); }
    console.log("connected to db");
});

[vagrant@localhost nodejs]$ mongo 192.168.33.10
MongoDB shell version v3.6.2
connecting to: mongodb://192.168.33.10:27017/test
2018-01-27T16:59:24.142+0900 W NETWORK  [thread1] Failed to connect to 192.168.33.10:27017, in(checking socket for error after poll), reason: Connection refused
2018-01-27T16:59:24.142+0900 E QUERY    [thread1] Error: couldn't connect to server 192.168.33.10:27017, connection attempt failed :
connect@src/mongo/shell/mongo.js:251:13
@(connect):1:6
exception: connect failed

やってみたこと
/etc/mongod.confの中を変更
参照ページ