13.4 Connecting to a Remote PostgreSQL Database

If your PostgreSQL database is installed on a separate server, you need to change the default settings in the postgresql.conf and pg_hba.conf files in the remote database.

Change the listening address in the postgresql.conf file.

By default, PostgreSQL allows to listen for the localhost connection. It does not allow a remote TCP/IP connection. To allow a remoteTCP/IP connection, add the following entry to the C:\NetIQ\idm\postgres\data\postgresql.conf file:
```
listen_addresses = '*'
```
If you have multiple interfaces on the server, you can specify a specific interface to be listened.
Add a client authentication entry to the pg_hba.conf file.

By default, PostgreSQL accepts connections only from the localhost. It refuses remote connections. This is controlled by applying an access control rule that allows a user to log in from an IP address after providing a valid password (the md5 keyword). To accept a remote connection, add the following entry to the C:\NetIQ\idm\postgres\data\pg_hba.conf file.
```
host all all 0.0.0.0/0 md5
```
For example, 192.168.104.24/26 trust

This works only for IPv4 addresses. For IPv6 addresses, add the following entry:
```
host all all ::0/0 md5
```
If you want to allow connection from multiple client computers on a specific network, specify the network address in the CIDR-address format in this entry.

The pg_hba.conf file supports the following client authentication formats.
- local database user authentication-method [authentication-option]
- host database user CIDR-address authentication-method [authentication-option]
- hostssl database user CIDR-address authentication-method [authentication-option]
- hostnossl database user CIDR-address authentication-method [authentication-option]
Instead of CIDR-address format, you can specify the IP address and the network mask in separate fields using the following format:
- host database user IP-address IP-mask authentication-method [authentication-option]
- hostssl database user IP-address IP-mask authentication-method [authentication-option]
- hostnossl database user IP-address IP-mask authentication-method [authentication-option]
Test the remote connection.
1. Restart the remote PostgreSQL server.
2. Log in to the server remotely using the username and password.