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nis_intro(7)
NAME
  nis_intro - Network Information Service (NIS) introductory information

DESCRIPTION
  The Network Information Service (NIS) is a distributed name service that
  allows participating hosts to share access to a common set of system and
  network files.  NIS allows the system administrator to manage these shared
  files on a single system.

  NIS is intended for use in a secure environment only, where gateways do not
  allow outside Internet access to the NIS protocol.

  NIS Maps

  Information distributed by NIS is stored in database files called maps.
  Most of the NIS maps represent files that were traditionally stored in the
  /etc directory.  These files include the following:

    ·  aliases

    ·  group

    ·  hosts

    ·  netgroups

    ·  networks

    ·  passwd

    ·  protocols

    ·  rpc

    ·  services

  In a secure environment, you can run NIS in a secure mode, thereby creating
  secure and nonsecure versions of the NIS maps.  See Security Administration
  for more information.

  You can also use NIS to distribute files used by Automount or AutoFS, or to
  distribute other user-defined files.

  Each NIS map contains a set of keys and associated values.  For example, as
  keys, the hosts map contains all host names on a network, and as values,
  the corresponding Internet addresses.	 Each NIS map has a map name, used by
  programs to access data in the map.

  NIS Domains

  A named set of NIS maps is called a domain.  A system's "domain name" or
  "NIS domain" corresponds to the set of NIS maps that the system can access.
  You can think of an NIS domain as a set of systems that share the same set
  of NIS maps.

  A system's domain name is set at the time the system is booted by the
  /sbin/init.d/nis script using an entry in the /etc/rc.config.common file.
  System administrators can use the nissetup script to place entries in this
  file.	 The nissetup script is described in the Network Administration:
  Services manual.

  You can determine your system's NIS domain using the domainname command.
  Refer to domainname(1). A domain name is required for retrieving data from
  an NIS database.

  NIS Client-Server Model

  NIS follows the client-server model of distributed services. There are two
  types of NIS servers - master and slave.  The master server stores the
  master copy of the NIS maps for its domain; these are the only NIS maps
  that can be modified.	 Each domain has only one master server.

  Slave servers store copies of the master server's NIS maps.  NIS slave
  servers can be spread throughout a network.  Whenever an NIS map is updated
  on the master server, the master propagates the changes to each slave
  server in its domain.	 If the master is unavailable for any reason, the
  slave servers continue to make the NIS maps available to the NIS clients.

  Clients are all of the systems that can access NIS maps.  When a client
  requires NIS information, it makes a remote procedure call (RPC) to one of
  the NIS servers to obtain the information.

  NIS Data Storage

  The data in NIS maps is stored as databases in dbm/ndbm, btree, or hash
  format.

  For example, the NIS map for the /etc/hosts file in the domain market might
  be stored in these dbm/ndbm files:

       /var/yp/market/hosts.byaddr.dir
       /var/yp/market/hosts.byaddr.pag
       /var/yp/market/hosts.byname.dir
       /var/yp/market/hosts.byname.pag

  The makedbm command takes an ASCII file such as /etc/hosts and converts it
  into dbm/ndbm files suitable for use by NIS. However, system administrators
  use the Makefile script in the /var/yp directory to create NIS map files
  and specify file format. The Makefile script then calls makedbm.

  Refer to the Network Administration: Services manual for details on the
  Makefile script, specifying different formats, and other NIS management
  information.

SEE ALSO
  Commands: domainname(1), svcsetup(8), ypbind(8), yppasswdd(8), ypserv(8),
  ypxfr(8)

  Files: svc.conf(4)

  Network Administration: Services

Index for Section 7

Alphabetical listing for N

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