Once we are past the initial stage, the next set of errors is a result of incorrect or missing entries in pg_hba.conf:, the host-based authentication file found under the data directory. The location/name of the file can be set using the hba_file parameter in postgresql.conf.

The most likely error we will see will be similar to the following:

psql: FATAL:  no pg_hba.conf entry for host "192.168.56.1", user "postgres", database "postgres"

The message mentions a host, a user, and a database. These are precisely the entries we should provide in pg_hba.conf. It has entries similar to the following screenshot:

The entry marked host can be a hostname, an IP address range or a special keyword.

We must reload the configuration for the changes to take effect with the following command:

pg_ctl reload

Now, we will be able to connect.

It's possible to use very specific entries in pg_hba...