Unhandled rejection MongoError: port must be specified

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According to the Mongoose docs you can connect to a MongoDB with a default port of 27017.

My mongod output ends with:

 I NETWORK  [initandlisten] waiting for connections on port 27017 

But when I try and connect to my database like this:

const mongoose = require('mongoose'); mongoose.connect('mongodb://localhost/myapp'); 

I get

Unhandled rejection MongoError: port must be specified 

What is happening here?

I have Mongoose v5.2.0, node v9.10.0, and MongoDB shell version v4.0.0.

If I change my connection string to include the port mongodb://localhost:27017/myapp then I am able to connect. But I'm not sure why I need this.


Port should also be specified in mongoose.connect() in the latest version of mongoose (5.2.0):


27017 is MongoDB's default port on which mongod is running.

Another solution is to revert to mongoose 5.1.7 which won't cause this issue:

npm install mongoose@5.1.7 --save 

Let me know if that fixes it.


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