Authentication Configuration
If you're doing a custom install and your system has a network card, Figure 8-32 lets you configure the type of password authentication your Red Hat Linux system will use. You will also have the opportunity to configure NIS support; If you are unsure as to whether or not you should do this, ask your network administrator.
Here's a brief explanation of the authentication password prompts:
Use Shadow Passwords -- provides a very secure method of retaining passwords for you. The /etc/passwd file is replaced by /etc/shadow which is only readable by root.
Enable MD5 Passwords -- allows a long password to be used (up to 256 characters) instead of the standard eight letters or less.
Enable NIS -- allows you to run a group of computers in the same Network Information Service domain with a common password and group file. There are two options here to choose from:
NIS Domain -- this option allows you to specify which domain or group of computers your system will belong to.
NIS Server -- this option causes your computer to use a specific NIS server, rather than "broadcasting" a message to the local area network asking for any available server to host your system.
Please Note: To configure the NIS option, you must be connected to an NIS network. If you are unsure whether or not you are connected to an NIS network, please ask you network administrator.
Unless you are setting up NIS, you will notice that both shadow passwords and MD5 passwords are selected. We recommend you use both to make your machine as secure as possible.