I am trying to connect to machine A (192.168.1.155) from a different machine B (192.168.1.180), with password transmitted as a MD5 string. I have the following lines in my pg_hba.conf file. host all all 192.168.1.180 255.255.255.1 md5 I created a database user "test_user": create user test_user with password 'test_passwd'; In A's database, I have select usename, passwd from pg_shadow; usename | passwd -----------+------------------------------------- postgres | pgbench | test_user | md5c573460a3b356e4610bfae406e1d8a9f Then I try to connect to A from B with the following: psql -h 192.168.1.155 -U test_user template1 Password for user test_user: (I typed test_passwd) psql: FATAL: password authentication failed for user "test_user"