Introduction
On-premises Microsoft Active Directory, Uplevel Active Directory compatible Directory Services, and cloud-based Azure Active Directory ( rebranded Microsoft Entra ID), all provide a central identity that can be used to manage user access to applications, services, or devices. They allow system administrators and Managed Service Providers the ability to centrally control large collections of user devices.
This choice in identity solutions offers the flexibility to use the most appropriate directory service for your organization's needs. For example, if you mostly manage cloud-only users that run tablets or other mobile devices, Azure Active Directory (Microsoft Entra ID) might be sufficient. However, if your user population requires workstations or laptops with centrally administered policies, audited access to resources, and high security levels, on-premises Active Directory (AD) will most likely be required. This document describes the use cases for each of these solutions.
High-Level Capabilities
Active Directory-based identity management from Microsoft and Uplevel share some common technologies; however, the various solutions serve different purposes and therefore offer different capabilities.
Microsoft Active Directory Compatible Domain Services (AD)
Traditional
Microsoft Active Directory Compatible Domain Services (AD) is built around an on-premises enterprise-class
LDAP server.
LDAP provides key features such as identity verification (with authentication via
Kerberos), computer object management, group policy administration (via
GPOs and
sysvol), and trust maintenance.
AD is widely used in a huge range of organizations to provide core user authentication and computer management, as well as to provide audited and controlled access to critical resources such as company data storage and applications.
Azure Active Directory (Microsoft Entra ID)
Azure Active Directory (Microsoft Entra ID) is not merely a cloud-based implementation of
AD. It is primarily aimed at user account and authentication services for mobile devices, and for mediating access to resources such as
Office 365 and other SaaS applications.
Microsoft Entra ID can be synchronized with an on-premises
AD environment to provide a single identity to users that works for both cloud and on-premises situations. Microsoft provides a software add-on called
Azure AD Connect to help perform this integration.
Core Functionalities of Azure AD (Microsoft Entra ID):
- Provides a cloud-first approach to management, enabling single-sign-on (SSO) access to cloud applications.
- Supports secure authentication with conditional access policies and multi-factor authentication.
- Supports unified identity within various platforms and applications, streamlining user access.
A third alternative exists:
Azure Active Directory Domain Services (AADDS). This mixes the functions of an on-premises
AD service with a cloud-based
AAD (
Microsoft Entra ID) service. It provides a subset of traditional
AD features such as domain join, group policy, and
Kerberos authentication, while still residing in the cloud. It can integrate and synchronize with
Microsoft Entra ID (which itself can replicate passwords with on-premises AD!). However, configuring and managing such a complex environment is technically challenging.
Note that AADDS, once set up, is a continuously billable service (i.e., it cannot be turned off without destroying the setup).
Uplevel Active Directory compatible Domain Services behaves very similarly to traditional Microsoft on-premises Active Directory (AD). It uses Kerberos as its authentication protocol, LDAP for directory services, and supports the traditional GPOs and sysvol for policy management. It gives small and midsize organizations most of the key capabilities of Microsoft Active Directory: the ability to gain control over their on-premises devices and applications by authentication, company-wide policy management, and mediating access to company resources. At the same time, it avoids the need to install and maintain a heavyweight enterprise-class server, and greatly simplifies management. Differences Between Azure AD (Microsoft Entra ID) and Traditional AD
Unlike traditional
AD,
AAD (Microsoft Entra ID) uses an entirely different software stack and an entirely different set of protocols. Rather than
Kerberos/NTLM and LDAP,
AAD (Microsoft Entra ID) uses
OAuth2 over HTTPS to support web-based
APIs and cloud applications.
OAuth2 can be used to perform authentication and authorization in most application types, but is mainly used by web apps and modern
REST API equipped applications. Traditional applications do not use
OAuth2 flows or
HTTPS transports.
Unlike Uplevel Active Directory, AAD (Microsoft Entra ID) is not Active Directory as we traditionally know it.
For example AAD (Microsoft Entra ID) :
- does not have the user and computer management functions expected from traditional AD.
- cannot enforce group policies, it cannot push GPOs to computers joining a domain.
- does not support OUs. Thus granular access controls cannot be supported.
- is not intended to control and audit access to on-premises storage, or control access to resources such as printers.
- does not support replication, and cannot be set up as a trusted domain to other domains.
- does not have Domain/Enterprise admin privilege, and does not support managed service accounts.
While
AAD (Microsoft Entra ID) is great for virtual machines hosted in
Azure - it is simple to set up and works well with your
Azure domain - it does not replace a proper domain controller.
AAD (Microsoft Entra ID) is mainly intended to support a cloud-only strategy where
Single Sign On (SSO) is the key focus.
Compliances
HIPAA
AAD (Microsoft Entra ID) cannot control what devices (workstations, servers) are permitted to join the network. This is essential for HIPAA compliance.