LDAP Vs AD: What’s the Difference?

Lightweight Directory Access Protocol (LDAP) and Active Directory (AD) are at the core of any company’s security. But what’s the difference between the two? LDAP is an open, vendor-agnostic, cross-platform protocol that works with multiple directory services, including AD.

AD, in contrast, is Microsoft’s proprietary directory service that organizes various IT assets like computers and users. Understanding the differences between LDAP and AD can help you protect your resources from critical security issues.

What Is LDAP?

LPAD vs AD LDAP is a lightweight protocol for accessing and managing directory services, particularly X.500-based directory services. However, unlike X.500-based directories that run on the open systems interconnection (OSI) model, LDAP runs on the transmission control protocol/internet protocol (TCP/IP) to transfer services.

LDAP is the core protocol used in Microsoft’s Active Directory. But you can also find its applications in other directory services such as Red Hat Directory Servers, Open LDAP, and IBM Security Directory Server.

The most common application of LDAP is authenticating users to an AD network. In this regard, LDAP stores usernames and passwords. You can then use different applications or services such as Jenkins, Kubernetes or Docker to validate an AD network’s credentials. As a protocol, LDAP only defines the “language” that clients can use to communicate with the servers (and that servers can use to communicate to servers).

LDAP doesn’t specify how programs operate on either the server or client side. For example, you could have an email program, address book, or printer browser as your client. The server, in contrast, can speak only LDAP or use other methods to transmit data. This way, LDAP is just an add-on.

There are currently two versions of LDAP: LDAPv2 (officially retired in 2003) and LDAPv3. LADPv3 emerged to address LDAPv2’s limitations, in areas such as authentication, internationalization, referrals and deployments. It leverages Kerberos v5 protocol via simple authentication and security layer (SASL) and incorporates more X.500 features than LDAPv2.

For Windows AD to work with LDAP, you need to authenticate users’ credentials against the Active Directory. The LDAP’s BIND operation sets the authentication state for any session when a client connects to the LDAP server. There are two LDAP authentication options: simple and SASL.

With simple authentication, the username and password create a BIND request to the server. SASL authentication, on the other hand, uses another authentication system such as Kerberos to bind the credentials to the LDAP server. SASL provides improved security since it separates application protocols from authentication methods, making the AD less vulnerable.

What Is AD?

AD is Microsoft’s directory service. Microsoft developed AD as part of its Windows domain networks to serve two functions. First, AD is a distributed hierarchical database where all information about IT assets, such as users, computers and other resources, gets stored. Second, AD comprises services that allow users to access and manipulate those resources.

In this regard, AD allows you to manage all the Windows domain network elements, including users, groups, computers, security policies and other user-defined objects. Active Directory leverages both LDAP and domain name system (DNS) to locate and access any resource on the network.

AD has two primary goals:

It allows users to access resources within the domain via a single sign-on (SSO).
It allows IT administrators to manage both users and other network resources centrally.

AD stores data as objects. An AD’s object is a single element such as a computer, user, shared folder, or printer. To categorize objects, AD uses names and attributes. For example, AD might store a user by using details such as username, password and secure shell (SSH) keys.

Below are the most common AD services:

Active Directory Domain Services (AD DS). AD DS is the primary component of AD. An AD DS organizes resources into logical hierarchies. It also controls which resources you can access on the network based on group policies. A domain controller (DC) is a server that hosts AD DS. Each AD must have at least one DC. Domain controllers are the containers that define domains, where each domain is a subset of an AD Forest. An AD Forest usually includes one or more domains that the DC organizes in organizational units (OUs).
Active Directory Lightweight Directory Services (AD LDS). AD LDS leverages LDAP and functions like AD DS. You can use AD LDS for directory-enabled applications that don’t require integration with a Windows domain network.
Active Directory Federation Services (AD FS). AD FS authenticates users to multiple applications via SSO. With SSO, you sign on only once to multiple services instead of using different authentication keys for each service.
Active Directory Certificate Services (AD CS). AD CS is an on-premises public-key infrastructure (PKI) mechanism that creates, validates and revokes certificates. It encrypts and decrypts emails, files and network traffic on the Windows domain network.
Active Directory Rights Management Services (AD RMS). AD RMS handles information rights and management on a Windows domain network. It can encrypt content, such as Excel files on a server, to restrict access.

How do LDAP and AD compare?

While LDAP and AD can work together to enhance the organizations’ overall security, they are different in terms of philosophy, functionality and standards. First, LDAP is an open application protocol and works outside of the Windows structure, focusing on Unix and Linux environments. AD, on the other hand, is Microsoft’s proprietary solution for accessing and managing directories.

Secondly, LDAP is a core protocol that can work with directory service providers like Active Directory, Red Hat Directory Servers, Open LDAP, and IBM Security Directory Server. It allows users to query and modify items in directories. On the other hand, AD is largely a directory service implementation with functionalities such as group and user management, policy administration, and authentication.

Third, LDAP does not have the same concepts as SSO since it is an open-source solution. In contrast, the AD supports domains and SSO. For example, you can set up SSO on clients to function across the domains if the network operating system (NOS) has multiple AD domains.

What is Active Directory Lightweight Directory Services (AD LDS)?

Active Directory Lightweight Directory Services (AD LDS) is a data storage and retrieval solution for organizations that want flexible support for their directory-based applications. AD LDS has the same code base as AD DS and therefore shares functionality with it. However, unlike AD DS, which runs domains, AD LDS runs on an application-by-application basis.

AD LDS leverages an LDAP directory service that supports directory-enabled applications without domain-related limitations and AD DS dependencies. It is a boon for IT administrators who want to use directory-based applications without integrating them with the Windows domain directory.

Since it doesn’t require DNS, you can run AD LDS on client operating systems such as windows workstations. You can also run multiple AD LDS instances concurrently on a single device, with an independent schema for each instance. For this reason, you can leverage AD LDS for software support and testing.

Parallels RAS Active Directory Integration

Active Directory can help you streamline security management across all Windows domain resources. You can also use AD to extend interoperability among various devices and applications. When properly implemented, AD can help you implement the organization’s network services, cybersecurity and resources effectively.

Parallels® Remote Application Server (RAS)—a complete virtual desktop infrastructure (VDI) solution—supports and uses AD. You can install Parallels RAS in both AD and workgroup environments where end-users and servers belong to the same Windows domain network or multiple forests with trust relationships.

Once installed, you can publish virtual applications and desktops and deliver them via multiple endpoints and platforms to users anywhere, anytime. When published, users can only access the applications and desktops if they get authenticated against AD. Besides, Parallels RAS supports multi-factor authentication mechanisms such as DeepNet, RADIUS and SafeNet, ensuring foolproof access to virtual desktops and applications.

Learn more about why Parallels RAS is the best-integrated solution for VDI by downloading your free 30-day trial!

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