So there is Fedora Core 3 with PostgreSQL 8.1.3 installed from rpms. The server listens on all interfaces. For testing, I used this pg_hba.conf (default with added line) and it worked: local all all trust host all all 127.0.0.1/32 trust host all all ::1/128 trust host all all 10.144.3.0/24 trust Very happy, I changed trust in the last line to MD5. The application (pgAdmin) stopped connecting (yes, sql user and its password was correct). No error, just "unable to connect" or something like this - I have localised version - in the status line. Is there something wrong with above file or maybe there are some missing libraries, of which I (and rpms) am not aware of? :( Thanks for any suggestions, Bart Golda