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Lightweight Directory Access Protocol

Swati Bansal


In today’s distributed computing environment, directories are required to locate resources. This paper describes the Lightweight Directory Access Protocol (LDAP), an open network protocol standard designed to provide access to distributed directories. LDAP provides a mechanism to query or modify information that exists in a directory information tree (DIT). Any combination of ADSI, the LDAP APIs, or a user searching the Active Directory through the User Interface (UI) results in the LDAP protocol being placed on the wire as the client communicates with the DSA. Because LDAP is a protocol standard it manifests itself in the same manner on the network wire, regardless of how the query or modification was generated at the application layer. This paper provides the information: 1. LDAP Fundamentals introduces the four models that describe LDAP and presents additional concepts that are relevant to the understanding of LDAP. 2. Core LDAP APIs describes the fundamental APIs that are used to expose the LDAP protocol. It is important to remember that LDAP is a network protocol standard, not a defined API standard. While there exist well-known APIs to access the LDAP protocol, each API is vendor-specific. The goal of this paper is not to analyze the different vendor implementations of LDAP APIs, but rather to study LDAP from a network protocol point of view. 3. Interpreting LDAP errors. In addition to the RFC-defined errors that are returned by a Directory Sever Agent (DSA) to a client, additional error information may be obtained from a network trace. How to interpret that error information is the focus of the final section.


Cite this Article
Swati Bansal. Lightweight directory access protocol (LDAP). Journal of Advances in Shell Programming. 2016; 3(1): 1–11p.


Directory, LDAP, Distinguished Name, BER, SASL, LDAP APIs, Network Trace, LDIF

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Dan Thompson, Understanding LDAP, White Paper.

V. Correy Wiiliams, LDAP, White Paper, 2000.

Understanding LDAP, International Technical Support Organization, IBM, June 1998. 4. Arkills B. LDAP Directories Explained: An Introduction and Analysis. Addison-Wesley Professional. ISBN 0-201-78792-X, 2003. 5. Carter G. LDAP System Administration. O'Reilly Media. ISBN 1-56592-491-6, 2003.

Donley C. LDAP Programming, Management, and Integration. Manning Publications. ISBN 1-930110-40-5, 2002.

Howes T, Smith M, Good G. Understanding and Deploying LDAP Directory Services. Addison-Wesley Professional. ISBN 0-672-32316-8, 2003.

Rhoton J. Programmer's Guide to Internet Mail: SMTP, POP, IMAP, and LDAP. Elsevier. ISBN 1-55558-212-5, 1999.

Voglmaier R. The ABCs of LDAP: How to Install, Run, and Administer LDAP Services. Auerbach Publications. ISBN 0-8493-1346-5, 2003.

Network Working Group RFC 4511. 2006-06-01. Retrieved 2014-04-04.

Directory Services LDAP. Retrieved 2014-04-04. 12. What is LDAP? Retrieved on 2013-07-17.

LDAP - Lightweight Directory Access Protocol. Retrieved 2014-04-05.

The X.500 series - ITU-T Rec. X.500 to X.521

Howes Tim. The Lightweight Directory Access Protocol: X.500 Lite, (PDF). Retrieved 26 December 2012.

Pre-History of LDAP. Cyber Matters. Retrieved 5 October 2014. 17. Service Name and Transport Protocol Port Number Registry. IANA. Retrieved 7 May 2014.

Global Catalog and LDAP Searches. 2014-08-05. Retrieved 2014-08-05.

Available at:

Zeilenga, K. LDAP Modify-Increment Extension. RFC 4525.

Zeilenga, K. Lightweight Directory Access Protocol (LDAP) Read Entry Controls. IETF. RFC 4527.

INTERNET-DRAFT LDAP Transactions draft-zeilenga-ldap-txn-15.txt


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