Can't create backup mongodump with --db. Authentication failed

Question

When I create backup of all databases in MongoDB (version 3):

mongodump --username bacUser --password 12345

It\'s OK. But when I try to cre

Answer 1

mongodump --host  --port 27017 --db   --authenticationDatabase admin --username  --password  --out ./Documents/

After all the trail, I found above working command to dump from mongdb.