Network Information Service (NIS) B.11.31.02 Administrator's Guide

1 Introduction
This chapter introduces you to Network Information Service (NIS) and its features. It also discusses
the components in an NIS network.
This chapter addresses the following topics:
• “Overview” (page 11)
• “NIS Network Components” (page 11)
• “NIS Naming Service Components” (page 12)
• “NIS Binding” (page 14)
• “Information Flow in an NIS Network” (page 14)
• “Startup Scripts in NIS Services” (page 16)
• “Features in NIS” (page 16)
Overview
NIS is a client/server directory service protocol that enables you to maintain a centralized
repository of system information, such as hosts, users, passwords, and other user-defined
information.
NOTE: NIS is not supported across WAN links (such as X.25 and SLIP).
NIS Network Components
This section discusses the components in an NIS network.
The NIS network consists of the following components:
• NIS Master Server
• NIS Slave Server
• NIS Client
NIS Master Server
An NIS master server holds the source files for all the NIS maps in the domain. Any changes to
the NIS maps must be made on the NIS master server. The NIS master server delivers information
to the NIS clients and supplies the NIS slave servers with up-to-date maps. The NIS maps are
stored on disk in the NIS master server. An NIS master server can also be an NIS client.
NIS Slave Server
An NIS slave server provides information to the NIS clients and takes the load off the NIS master
server. The NIS maps are created on the NIS master server and then transferred to the slave
servers. On the slave servers, the maps are stored in the memory. Changes to the NIS maps must
be made on the NIS master server, which then transfers the updated copies of the maps to the
NIS slave servers.
NIS Client
An NIS client is a system that obtains its configuration information from either an NIS master
server or an NIS slave server.
You can configure the NIS client using the ypinit-c command. The ypinit -c command
configures the local host as an NIS client to bind the NIS client to a particular NIS server. When
you invoke the ypinit -c command, the system prompts you to construct a list of NIS servers
in the order of preference. The client tries to bind to the NIS servers in the order specified in the
/var/yp/binding/<domain_name>/ypservers file.
Overview 11