LDAP Naming Services Compared to Other Naming Services

The following table shows a comparison between the DNS, NIS, NIS+, and LDAP naming services.

	DNS	NIS	NIS+	LDAP
Namespace	Hierarchical	Flat	Hierarchical	Hierarchical
Data Storage	Files/resource records	2 column maps	Multi-columned tables	Directories (varied) Indexed database
Servers	Master/slave	Master/slave	Root master/ non-root master; primary/ secondary; cache/stub	Master/replica Multi master replica
Security	None	None (root or nothing)	Secure RPC (AUTH_DH) Authentication	SSL, varied
Transport	TCP/IP	RPC	RPC	TCP/IP
Scale	Global	LAN	LAN	Global

Advantages of LDAP Naming Services

LDAP enables you to consolidate information by replacing application-specific databases, which reduces the number of distinct databases to be managed.
LDAP allows data to be shared by different naming services.
LDAP provides a central repository for data.
LDAP allows for more frequent data synchronization between masters and replicas.
LDAP is multi-platform and multi-vendor compatible.

Restrictions of LDAP Naming Services

Following are some restrictions associated with LDAP naming services:

Clients prior to Solaris 8 are not supported.
An LDAP server cannot be its own client.
Setting up and managing an LDAP naming services is more complex and requires careful planning.
A NIS client and a Native LDAP client cannot co-exist on the same client machine.

Note - A directory server (an LDAP server) cannot be its own client. That is, you cannot configure the machine that is running the directory server software to become an LDAP naming services client.