If you upgrade a ZENworks Server from ZENworks 7 Linux Management with IR1 to ZENworks 7.3 Linux Management, the default PostgreSQL database security level requires authentication, but you can optionally increase the security level of the database. In most corporate settings, the PostgreSQL database resides on a corporate LAN with firewall protection. If you want to increase the security level of the database, edit the /var/lib/pgsql/pg_hba.conf file to add the IP address and subnet mask for the ZENworks Primary Server and for all ZENworks Secondary Servers as well as for the local host. An unedited file has a series of zeroes in place of the IP addresses and subnet masks; you replace the zeroes with the information for your primary and secondary ZENworks servers.
If you upgrade from ZENworks 7 Linux Management - Dell Edition, this process is not necessary. See the PostgreSQL documentation for more information.