The default settings applied to system login are based on what Red Hat deems basic security. If, for some reason, you want to change this, this recipe will show you a couple of examples. Authconfig has two tools that you can use to configure authentication: authconfig and authconfig-tui.
These two tools configure pam for you in such a way that the changes are consistent throughout rpm updates.
The authconfig-tui tool is not as feature-rich as the plan authconfig tool, which I personally recommend you to use as it allows you to do more.
You can manually edit the files located in /etc/pam.d if and when you know what you're doing, but this is not recommended.
Perform the following steps:
First, change the hash encryption of the passwords stored in /etc/shadow to sha512, as follows:
~]# authconfig --passalgo=sha512 --update
Enable NIS authentication through the following command:
~]# authconfig --enablenis –nisdomain=NISDOMAIN --nisserver=nisserver.example.com...