System Administration Guide: Naming and Directory Services (DNS, NIS, and LDAP)


application-level naming service

Application-level naming services are incorporated in applications offering services such as files, mail, and printing. Application-level naming services are bound below enterprise-level naming services. The enterprise-level naming services provide contexts in which contexts of application-level naming services can be bound.


Each LDAP entry consists of a number of named attributes each of which has one or more values.


The means by which a server can verify a client's identity.


The DN where part of the DIT is rooted. When this is the baseDN for a NIS domains entries it is also referred to as a context.

cache manager

The program that manages the local caches of NIS+ clients (NIS_SHARED_DIRCACHE), which are used to store location information about the NIS+ servers that support the directories most frequently used by those clients, including transport addresses, authentication information, and a time-to-live value.

child domain

See domain.


(1) The client is a principal (machine or user) requesting an naming service from an naming server.

(2) In the client-server model for file systems, the client is a machine that remotely accesses resources of a compute server, such as compute power and large memory capacity.

(3) In the client-server model, the client is an application that accesses services from a “server process.” In this model, the client and the server can run on the same machine or on separate machines.

client-server model

A common way to describe network services and the model user processes (programs) of those services. Examples include the name-server/name-resolver paradigm of the Domain Name System (DNS). See also client.


The authentication information that the client software sends along with each request to a naming server. This information verifies the identity of a user or machine.

data encrypting key

A key used to encipher and decipher data intended for programs that perform encryption. Contrast with key encrypting key.

data encryption standard (DES)

A commonly used, highly sophisticated algorithm developed by the U.S. National Bureau of Standards for encrypting and decrypting data. See also SUN-DES-1.


DBM is the database originally used to store NIS maps.

decimal dotted notation

The syntactic representation for a 32-bit integer that consists of four 8-bit numbers written in base 10 with periods (dots) separating them. Used to represent IP addresses in the Internet as in:


See data encryption standard (DES).


(1) An LDAP directory is a container for LDAP objects. In UNIX, a container for files and subdirectories.

directory cache

A local file used to store data associated with directory objects.

directory information tree

The DIT is the distributed directory structure for a given network. By default, Solaris LDAP clients access the information assuming that the DIT has a given structure. For each domain supported by the LDAP server, there is an assumed subtree with an assumed structure.

distinguished name

A distinguished name is an entry in an X.500 directory information base (DIB) composed of selected attributes from each entry in the tree along a path leading from the root down to the named entry.


See directory information tree.


A distinguished name in LDAP. A tree-like structured addressing scheme of the LDAP directory which gives a unique name to each LDAP entry.


See Domain Name System.


An NIS server or an NIS+ server with NIS compatibility set forwards requests it cannot answer to DNS servers.

DNS zone files

A set of files wherein the DNS software stores the names and IP addresses of all the workstations in a domain.

DNS zones

Administrative boundaries within a network domain, often made up of one or more subdomains.


(1) In NIS+ a group of hierarchical objects managed by NIS+. There is one highest level domain (root domain) and zero or more subdomains. Domains and subdomains may be organized around geography, organizational or functional principles.

  • Parent domain. Relative term for the domain immediately above the current domain in the hierarchy.

  • Child domain. Relative term for the domain immediately below the current domain in the hierarchy.

  • Root domain. Highest domain within the current NIS+ hierarchy.

(1) In the Internet, a part of a naming hierarchy usually corresponding to a Local Area Network (LAN) or Wide Area Network (WAN) or a portion of such a network. Syntactically, an Internet domain name consists of a sequence of names (labels) separated by periods (dots). For example,

(2) In International Organization for Standardization's open systems interconnection (OSI), “domain” is generally used as an administrative partition of a complex distributed system, as in MHS private management domain (PRMD), and directory management domain (DMD).

domain name

The name assigned to a group of systems on a local network that share DNS administrative files. The domain name is required for the network information service database to work properly. See also domain.

Domain naming service (DNS)

A service that provides the naming policy and mechanisms for mapping domain and machine names to addresses outside of the enterprise, such as those on the Internet. DNS is the network information service used by the Internet.


The means by which the privacy of data is protected.

encryption key

See data encrypting key.

enterprise-level network

An “enterprise-level” network can be a single Local Area Network (LAN) communicating over cables, infra-red beams, or radio broadcast; or a cluster of two or more LANs linked together by cable or direct phone connections. Within an enterprise-level network, every machine is able to communicate with every other machine without reference to a global naming service such as DNS or X.500/LDAP.


A single row of data in a database table, such as an LDAP element in a DIT.


A NIS map entry might consist of a number of components and separator characters.


See group ID.

global naming service

A global naming service identifies (names) those enterprise-level networks around the world that are linked together by phone, satellite, or other communication systems. This world-wide collection of linked networks is known as the “Internet.” In addition to naming networks, a global naming service also identifies individual machines and users within a given network.

group ID

A number that identifies the default group for a user.

indexed name

A naming format used to identify an entry in a table.

Internet address

A 32-bit address assigned to hosts using TCP/IP. See decimal dotted notation.


Internet Protocol. The network layer protocol for the Internet protocol suite.

IP address

A unique number that identifies each host in a network.

key (encrypting)

A key used to encipher and decipher other keys, as part of a key management and distribution system. Contrast with data encrypting key.

key server

A Solaris operating environment process that stores private keys.


Lightweight Directory Access Protocol is a standard, extensible directory access protocol used by LDAP naming service clients and servers to communicate with each other.

local-area network (LAN)

Multiple systems at a single geographical site connected together for the purpose of sharing and exchanging data and software.

mail exchange records

Files that contain a list of DNS domain names and their corresponding mail hosts.

mail hosts

A workstation that functions as an email router and receiver for a site.


The process of converting NIS entries to or from DIT entries. This process is controlled by a mapping file.

master server

The server that maintains the master copy of the network information service database for a particular domain. Namespace changes are always made to the naming service database kept by the domain's master server. Each domain has only one master server.


Management information systems (or services).

N2L server

NIS-to-LDAP server. An NIS master server that has been reconfigured as an N2L server by using the N2L service. Reconfiguration includes replacing NIS daemons and adding new configuration files.

name resolution

The process of translating workstation or user names to addresses.

name server

Servers that run one or more network naming services.


(1) A namespace stores information that users, workstations, and applications must have to communicate across the network.

(2) The set of all names in a naming system.

naming service

A network service that handles machine, user, printer, domain, router, an other network names and addresses.

naming service switch

A configuration file (/etc/nsswitch.conf) that defines the sources from which an naming client can obtain its network information.


NDBM is an improved version of DBM.

network mask

A number used by software to separate the local subnet address from the rest of a given Internet protocol address.

network password

See Secure RPC password.


A distributed network information service containing key information about the systems and the users on the network. The NIS database is stored on the master server and all the replica or slave servers.


A distributed network information service containing hierarchical information about the systems and the users on the network. The NIS+ database is stored on the master server and all the replica servers.

NIS-compatibility mode

A configuration of NIS+ that allows NIS clients to have access to the data stored in NIS+ tables. When in this mode, NIS+ servers can answer requests for information from both NIS and NIS+ clients.

NIS maps

A file used by NIS that holds information of a particular type, for example, the password entries of all users on a network or the names of all host machines on a network. Programs that are part of the NIS service query these maps. See also NIS.

parent domain

See domain.

preferred server list

A client_info table or a client_info file. Preferred server lists specify the preferred servers for a client or domain.

private key

The private component of a pair of mathematically generated numbers, which, when combined with a private key, generates the DES key. The DES key in turn is used to encode and decode information. The private key of the sender is only available to the owner of the key. Every user or machine has its own public and private key pair.

public key

The public component of a pair of mathematically generated numbers, which, when combined with a private key, generates the DES key. The DES key in turn is used to encode and decode information. The public key is available to all users and machines. Every user or machine has their own public and private key pair.


Relative Distinguished Name. One part of a DN.


See entry.

remote procedure call (RPC)

An easy and popular paradigm for implementing the client-server model of distributed computing. A request is sent to a remote system to execute a designated procedure, using arguments supplied, and the result is returned to the caller.

reverse resolution

The process of converting workstation IP addresses to workstation names using the DNS software.

RFC 2307

RFC specifying a mapping of information from the standard NIS maps to DIT entries.

root domain

See domain.


See remote procedure call (RPC).


The simple authentication and security layer. A framework for negotiating authentication and security layer semantics in application-layer protocols.


A set of rules defining what types of data can be stored in any given LDAP DIT.


A description of where to look for a given attribute in the DIT. The searchTriple is composed of a 'base dn', 'scope' and 'filter'. This is part of the LDAP URL format as defined in RFC 2255.

Secure RPC password

Password required by Secure RPC protocol. This password is used to encrypt the private key. This password should always be identical to the user's login password.


(1) In NIS+, NIS, DNS, and LDAP a host machine providing naming services to a network.

(2) In the client-server model for file systems, the server is a machine with computing resources (and is sometimes called the compute server), and large memory capacity. Client machines can remotely access and make use of these resources. In the client-server model for window systems, the server is a process that provides windowing services to an application, or “client process.” In this model, the client and the server can run on the same machine or on separate machines.

(3) A daemon that actually handles the providing of files.

server list

See preferred server list.

slave server

A server system that maintains a copy of the NIS database. It has a disk and a complete copy of the operating environment.

(2) Slave servers are called replica servers in NIS+.


NIS source files


SSL is the secure sockets layer protocol. It is a generic transport-layer security mechanism designed to make application protocols such as LDAP secure.


A working scheme that divides a single logical network into smaller physical networks to simplify routing.


In LDAP, the distinguished name (DN) of the DIT.


In NIS+ a two-dimensional (nonrelational) database object containing NIS+ data in rows and columns. (In NIS an NIS map is analogous to a NIS+ table with two columns.) A table is the format in which NIS+ data is stored. NIS+ provides 16 predefined or system tables. Each table stores a different type of information.


See Transport Control Protocol (TCP).


Acronym for Transport Control Protocol/Interface Program. The protocol suite originally developed for the Internet. It is also called the Internet protocol suite. Solaris networks run on TCP/IP by default.

Transport Control Protocol (TCP)

The major transport protocol in the Internet suite of protocols providing reliable, connection-oriented, full-duplex streams. Uses IP for delivery. See TCP/IP.

Transport Layer Security (TLS)

TLS secures communication between an LDAP client and the directory server, providing both privacy and data integrity. The TLS protocol is a super set of the Secure Sockets Layer (SSL) protocol.

wide-area network (WAN)

A network that connects multiple local-area networks (LANs) or systems at different geographical sites by phone, fiber-optic, or satellite links.


A global-level directory service defined by an Open Systems Interconnection (OSI) standard. A precursor to LDAP.


Yellow PagesTM. The old name for NIS which is still used within the NIS code.