LDAP vs Active Directory – What’s the Difference ? (Explained)

Quite often, some people get confused between LDAP vs Active Directory. They consider both as same. But in reality, both are different. One is a protocol, while the other is a proprietary product. LDAP was inspired and primarily established from the requirement to manage the telephone directory. At the same time, the AD or Active Directory implements LDAP. This article will try to explain the difference between LDAP and Active Directory (AD).

LDAP vs Active Directory

LDAP - A Protocol

LDAP-OpenLDAP Protocol

LDAP or Lightweight Directory Access Protocol is an open standard that queries items in directory services. It is a product-agnostic protocol and authenticates directory services.  It also manages distributed directory information.  Various directory services implement LDAP, which provides interoperability among various 3rd party applications.

 

LDAP runs over the TCP/IP stack, and LDAP controls directory access. It is implemented mainly with open-source tools.

TCP-IP-stack
TCP/IP Stack Architecture

Active Directory - User Management

Active Directory is a proprietary product from Microsoft. It is a directory services database that provides authentication, user and group management, policy management and administration and much more in a windows platform. You will find AD offered as services and processes in most of the MS server OS platforms. Active Directory uses LDAP (version 2 and 3), Kerberos and DNS.

You can check out the article Active Directory in the cloud to know more about setting up active directory in the in the cloud. 

LDAP Directory Structure

LDAP Directory structure
LDAP Directory structure

An LDAP directory consists of a tree structure. The topmost object or entry is the root. The root can be the organization that owns the directory. All the objects in the directory are positioned as per a hierarchy called the Directory information tree (DIT). The complete path to an object is called a distinguished name or DN. A single node along the path to the object is called a relative distinguished name (RDN). Here are the technical terms:-

 

  • Entry or Object – Consists of information related to a particular entity. For example, an Employee entry or object has information such as first name, last name and email.
  • Root Object – The topmost entry in the directory is called root object, and it represents the organization that owns the entire directory.
  • Distinguished Names – Unique identifier for an entry at respective hierarchy. It is also a path that traces the entry in the directory tree structure. For example,
  • cn=John Doe, ou=People, dc=sun.com
  • Relative Distinguished Name- A component of Distinguished Name. It is also a partial path to the entry in the directory relative to another entry in the directory. For example, in the DN component.
  • cn=John Doe, ou=People  is the RDN.
  • Container – A container is an entry that can hold another entry or group of entries or objects. In the above image, the root object contains employee entries.
  • Leaf – A leaf structure corresponds to the entry which does not contain any other entry.

Logical Structure of Active Directory

Active Directory consists of two parts. One is a database, and another is the execution part. The execution part consists of an execution code that will manage the database and service various requests. The execution part is also known as Directory System Agent, and it consists of multiple windows services and processes. Database objects are accessible via LDAP, Kerberos, APIs and security accounts manager services.

Active Directory features

The logical structure of Active Directory consists of the following components:

 

  • Objects – They are categorized into resources and security principles. Objects can be any single entity such as a user, groups, computer etc.
  • Forests, trees, and domains – All the objects are divided into three levels or tiers or divisions. Objects or assets that share the same database fall into domain level. For instance ‘HR department’. A group of domains fall into trees. At the same time, a forest is a collection of trees that share a global directory or schema.
  • Organizational units – Each entity within a domain is structured as an organizational unit (OU)—for example, HR, marketing, etc.
  • Shadow groups – A regular Active Directory security group containing objects or users found under an Organizational unit.
  • Partitions – Database is organized into partitions where each partition corresponds to specification types, and replication scope and the partitions are referred to as ‘Naming Contexts’.

Active Directory Services

Active Directory offers several services; here are few of them:

 

  • Domain Services – This service stores all the information about various domains in the windows network.
  • Lightweight Directory Services – An implementation of LDAP.
  • Certificate Services is a public key infrastructure service that validates, creates, and revokes certificates for the applications.
  • Federation Services is a single-sign-on service, which means that users can access multiple applications with a single credential using ADFS.
  • Rights Management Services manages the information rights and uses encryption to limit access to various applications such as word documents, emails, etc.

Primary Focus area of LDAP

LDAP focuses on the following:

 

  • Directory structure – Each entry or object in the directory is distinguishable by DN or distinguished name. DN is used for querying the entire directory.
  • Data Modification – This protocol has been designed for quick searching of data and reading the same.
  • Flexible Authentication. Provides flexible authentication, be it using a username password, Kerberos token or an encrypted key.
  • Search at scale – Servers based on LDAP are designed to run highly scalable queries and quickly search data sets.

Using LDAP with Active Directory

LDAP integration is a crucial feature of Active Directory, allowing you to control access to your network more efficiently. In reality, various directory services and access management solutions may use LDAP,  making it a popular choice in different situations, especially those that don’t use Active Directory.

LDAP vs Active Directory - A comparison

LDAP

Active Directory

Type

Open Standard

Proprietary Product

OS supported

Linux, Windows, Mac Os

Windows

Functionality

Protocol to interact with directory services and maintain distributed directory information.

Directory services database, creates and manages, user, group and policies. 

Device Management

NA

Through GPOs or Group Policy Objects.

Versions

LDAP v2, LDAPv3

corresponds to schema version 13,30,31,44,47,56,69,87,88,

Flexibility

Highly Flexible

Less Flexible

Dependency

None

Microsoft Domain Controller

Services offered

None

  • Domain Services (AD DS) 
  • Lightweight Directory Services (AD LDS)
  • Federation Services (AD FS)  
  • Certificate Services (AD CS)
  • Rights Management Services (AD RMS)

LDAP vs Active Directory - Final Thoughts

By now, it should be evident that AD and LDAP are not interchangeable, but they can operate together to your company’s or organization’s advantage. As a directory service, Microsoft’s Active Directory (AD) provides limited access to vital information about persons within an organization. On the other hand, LDAP is a non-Microsoft protocol that allows users to query an Active Directory and authenticate access to it.


By working in concert with each other, AD and LDAP may be used to provide your company or organization with vital information, information that is both available internally and safe from external actors who may seek to access it. We cannot overstate the necessity of understanding these concepts and applying them in ways suited to your business in this day and age when digital security cannot be comprehensive enough.

Avatar for Bhaskar Narayan Das
Bhaskar Narayan Das

Data analytics, Cloud development and software development are my passions. I have extensive knowledge in Java and the AWS platform. I am currently one of Cloud Infrastructure Services technical writers.

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