title: failed to connect to server on first connect. But sometimes it working after restat internet connection
body: <p>What to do about this error?</p>
  
  <blockquote>
    <p>Server Running on port 5000 { MongoNetworkError: failed to connect to
    server [ds231242.mlab.com:31242] on first connect [MongoNetworkError:
    getaddrinfo ENOTFOUND ds231242.mlab.com ds231242.mlab.com:31242]
        at Pool. (C:\MERNapps\TestMERN14\node_modules\mongodb-core\lib\topologies\server.js:564:11)
        at emitOne (events.js:116:13)
        at Pool.emit (events.js:211:7)
        at Connection. (C:\MERNapps\TestMERN14\node_modules\mongodb-core\lib\connection\pool.js:316:12)
        at Object.onceWrapper (events.js:317:30)
        at emitTwo (events.js:126:13)
        at Connection.emit (events.js:214:7)
        at Socket. (C:\MERNapps\TestMERN14\node_modules\mongodb-core\lib\connection\connection.js:245:50)
        at Object.onceWrapper (events.js:315:30)
        at emitOne (events.js:116:13)
        at Socket.emit (events.js:211:7)
        at emitErrorNT (internal/streams/destroy.js:64:8)
        at _combinedTickCallback (internal/process/next_tick.js:138:11)
        at process._tickCallback (internal/process/next_tick.js:180:9)   name: 'MongoNetworkError',   errorLabels: [
    'TransientTransactionError' ],   [Symbol(mongoErrorContextSymbol)]: {}
    }</p>
  </blockquote>