PostgreSQL keeps asking for user password with "trust" authentication enabled

Question

I created a user john with createuser and didn't supply any passwords for it, i.e. no -P option specified. I then proceeded to add the following line above all other lines in the pg_hba.conf file:

host all john 127.0.0.1/32 trust

I then restarted the server but even after that, when I try to run psql -U john it keeps asking for a password. I even ran the command psql -c "alter role john with password null;" but it changed nothing. PostgreSQL keeps asking for a password for john. What am I missing?

Running PostgreSQL 13.2 on Windows 10.

Answer 1

By checking the logs, it got apparent that PostgreSQL was matching the ::1/128 IPv6 address, which had scram-sha-256 as its authentication method. adding a line like

host all john ::1/128 trust

fixed the problem.

Also, there is no need for restarting the DBMS after changes to pg_hba.conf.