Integrating NIS into System

In a network running NIS, many of the standard system configuration files (/etc/passwd, /etc/group, and others) are at least partially replaced with information obtained from NIS. The programs and system calls that use this information must know to obtain it from NIS, rather than from the usual files. For example, if NIS distributes network passwords, the system libraries concerned with login procedures must “know” to consult the NIS database to verify a correct password, rather than using the file

/etc/passwd.

passwd: files nis
group: files nis

mean that, for information about passwords and groups, first consult the local files (/etc/passwd and /etc/group), then consult NIS. By setting the order of keys in the /etc/nsswitch.conf file, you can cause local data in the /etc/passwd file to override information in an NIS map. The usual options for data sources in /etc/nsswitch.conf are

NIS (Network Information Service) is a system that allows for centralized management of user accounts, passwords, and other system information across a network. To integrate NIS into an Ubuntu operating system, the following steps can be taken:

1. Install the necessary packages: The nis package needs to be installed on the Ubuntu system in order to enable NIS support. This can be done using the following command:

   sudo apt-get install nis
   

   
   
2. Configure the NIS domain name: The NIS domain name must be set on the Ubuntu system. This can be done by editing the /etc/defaultdomain file and adding the NIS domain name.
3. Configure NIS client settings: The NIS client settings need to be configured on the Ubuntu system to connect to the NIS server. This can be done by editing the /etc/yp.conf file and adding the IP address or hostname of the NIS server.
4. Configure NSSwitch: The nsswitch.conf file needs to be updated to include NIS as a source for user and group information. This can be done by adding nis to the passwd, shadow, and group lines in the file.
5. Restart NIS services: The NIS services need to be restarted to apply the changes. This can be done using the following command:
   

   sudo /etc/init.d/nis restart
   

After these steps are completed, the Ubuntu system should be able to connect to the NIS server and access the centralized user and system information. It's important to note that the specific steps and commands required to integrate NIS into an Ubuntu system may vary depending on the version of Ubuntu and the specific NIS server being used. It's recommended to consult the relevant documentation or seek guidance from experienced system administrators for more detailed guidance.

On Solaris systems, you can use many commands to extract information from NIS (or more likely NIS+) maps. The indicator of such behavior is a plus sign (+), which means “consult NIS or NIS+ for this piece of information.” Here is a concrete example, with comments, from the startup script

/etc/rc2.d/S72inetsvc 

on a Solaris machine:

# This is third phase of TCP/IP startup/configuration. 
# This script runs after the NIS/NIS+ startup
# script. We run things here that may
# depend on NIS/NIS+ maps. 
#
# XXX - We need to give ypbind time to
# bind to a server.
#
sleep 5
#
# Re-set the netmask and broadcast addr for all 
# IP interfaces. This ifconfig is run here, after
# NIS has been started, so that netmask +" will
# find the netmask if it lives in a NIS map.
#
/usr/sbin/ifconfig -au netmask + broadcast +

Here Solaris passes the netmask + and broadcast + arguments to ifconfig, which means the netmask will be extracted from the “netmasks” NIS map on this Solaris machine, if NIS is running.
Solaris systems integrate NIS most strongly into the operations of the system.