Sometimes an organization needs a convenient way to gather, store, and distribute information for access by the applications that need it. The Lightweight Directory Access Protocol (LDAP) simplifies the process of creating and using directories of information by network-ready applications.
The intention of LDAP is to simplify the overhead needed to provide directory services described in the X.500 specification. LDAP is actually a subset of X.500 features. By standardizing the structure of database information, LDAP can get around proprietary storage formats to allow many different applications to share the same data.
X.500 is a CCITT specification that has become part of the Open Systems Interconnection (OSI) standards that define a layered framework for interconnecting networks and related services. With the dominance of TCP/IP networks (such as the Internet) in the world, OSI never became the predominent network framework that some expected it to be. Despite that, the seven-layer OSI reference model is often used in classrooms to teach networking theory. Likewise some ot these specifications, such as X.500, have been adopted (and sometimes adapted) where standard, cross-platform features are required.
Fedora Core systems include OpenLDAP software packages to implement LDAP server and client services. To illustrate how to configure and use an LDAP server with OpenLDAP, and make it accessible to user applications, this chapter goes through the process of setting up a shared address book on your Fedora Core system. It also describes how to use e-mail clients that can access the LDAP address book.