Lesson 1

Organizations want their networks to be powerful communication systems that are easy to use. A large network is not just a simple collection of computers that communicate with each other, it is a complex system that requires a well-thought out plan in order for it to function smoothly. You can facilitate the use of a network by presenting users with consistent configuration and interfaces on all computers. For example, you could use the same username and password on all computers on your network. But, keeping consistent information on all hosts can be a daunting task if you edit each and every computer's configuration files. It is more efficient to have a central location for the information on a network. The Network Information Service (NIS) allows you to do just this. You can provide authentication (usernames and passwords), hostnames, protocols, and many other types of information to computers from one or more servers. In this module, you will learn about the tools and files involved in configuring the client's use of NIS.

NIS (Network Information System) is a client-server networking protocol used in Red Hat Linux to manage user and group information across a network. NIS provides a centralized database of user and group information that can be accessed by NIS clients on the network. In Red Hat Linux, NIS clients are configured to use the NIS server as the primary source for user and group information. This allows users to log in to any machine on the network using their NIS username and password, and access their files and applications.
To use NIS Client Networking in Red Hat Linux, the following steps are typically required:

1. Install the NIS client software: The NIS client software is typically included with Red Hat Linux, and can be installed using the package manager or command line utilities.
2. Configure the NIS client: The NIS client must be configured to use the NIS server as the primary source for user and group information. This is done by editing the /etc/yp.conf file and adding the IP address or hostname of the NIS server.
3. Set the NIS domain name: The NIS client must be configured with the NIS domain name, which is used to identify the NIS server and the NIS database. This is done by editing the /etc/defaultdomain file and adding the NIS domain name.
4. Configure the Name Service Switch: The Name Service Switch (NSS) is used to configure the order in which various databases are searched for user and group information. The NSS configuration file (/etc/nsswitch.conf) must be edited to include NIS as one of the sources for user and group information.
5. Start the NIS client service: The NIS client service must be started to enable the NIS client to access the NIS server and database. This is typically done using the service command or systemd.

Once the NIS client is configured and running, users can log in to any machine on the network using their NIS username and password, and access their files and applications. The NIS client will automatically retrieve user and group information from the NIS server and database, ensuring that the same user and group information is available across the network.

1. Describe the Network Information System
2. Obtain information about the network
3. Describe the function and purpose of nsswitch.conf
4. Use authconfig to configure an NIS client machine
5. Edit configuration files for the NIS client manually
6. Test the NIS client machine

The next lesson describes the Network Information System.

If your network uses NIS centrally to administer users, groups, network addresses, and other information, you can set up your Red Hat Linux system to use that information as an NIS client. To configure Red Hat Linux as an NIS client, you need to get the following information from your NIS administrator:

1. NIS Domain Name: This is a keyword used to describe the group of hosts that use the common set of NIS files. Domain name is an unfortunate way of referring to this keyword, because it does not have anything to do with the TCP/IP domain name. Its only similarity is that it refers to a group of computers.
2. NIS Master Server Name: This is the name of the computer on your network that maintains the NIS databases and responds to requests from the network for that information.
3. NIS Slave Server Names: An NIS domain may have more than one NIS server that can handle requests for information from the domain's NIS database. An NIS slave server keeps copies of the NIS maps so that it can respond to requests if the master NIS server goes down. (NIS slave servers are optional.)

When you installed Red Hat Linux, if you knew that your network used NIS, you could have selected NIS as the way to handle user names and passwords on your computer. If you have not already configured NIS for your computer, the procedures that follow will describe how to do that. The procedures consist of defining your NIS domain name, setting up the /etc/yp.conf file, and configuring NIS client daemons (ypbind and ypwhich) to start when you boot your system.