You mean to remove both mongodb-23654.sock and mongodb-27017.sock?

> sudo rm /tmp/mongodb-23654.sock
> sudo rm /tmp/mongodb-27017.sock

Well the 27017 should have been created once I have changed for a while the mongod.conf

This kind of suggestions
sudo chown mongodb:mongodb /tmp/mongodb-27017.sock
were posted along with other suggested solutions in StackOverflow actually…