Choosing the Right Tool for Active Directory Synchronization
Introduction
Active Directory synchronization is a common requirement for modern IT environments. However, not all synchronization tools are built for the same purpose. Many organizations assume that Microsoft Entra ID Sync (formerly Azure AD Connect) can handle all identity synchronization needs, but that is not always the case.
This article explains the differences between MachSync and Microsoft Entra ID Sync, including where each tool fits, what problems they solve, and which scenarios they are designed for. The goal is to help IT teams choose the right approach based on how their Active Directory environments are structured.
What Is MachSync?
MachSync is an Active Directory synchronization solution designed to keep identities consistent between multiple Active Directory forests. It synchronizes users, passwords, groups, organizational units, and selected attributes directly from one AD forest to another.
MachSync works without domain or forest trusts and runs fully within customer-controlled infrastructure. Identity data does not need to pass through cloud services or external platforms. This makes it suitable for on-premise, private cloud, regulated, and disconnected environments.
MachSync is commonly used for:
- Forest-to-forest Active Directory synchronization
- Mergers and acquisitions
- Active Directory migrations
- Hybrid and private cloud environments
- MSP and hosted AD models
What Is Microsoft Entra ID Sync (Azure AD Connect / Cloud Sync)?
Microsoft Entra ID Sync, including Azure AD Connect and Entra Cloud Sync, is designed to synchronize identities from on-premise Active Directory to Microsoft Entra ID.
Its main purpose is to enable users to access Microsoft 365 and other Entra-integrated services using their on-premise credentials. It is a cloud-focused identity provisioning tool, not an Active Directory–to–Active Directory synchronization solution.
Entra ID Sync relies on Microsoft Entra ID as the central identity platform. It does not provide native support for syncing identities directly between two or more Active Directory forests.
Core Difference at a Glance
The most important distinction is simple:
- MachSync synchronizes Active Directory to Active Directory
- Microsoft Entra ID Sync synchronizes Active Directory to Entra ID
They are built for different identity models and solve different problems.
Feature Comparison: MachSync vs Microsoft Entra ID Sync
| Feature / Capability | MachSync | Microsoft Entra ID Connect / Cloud Sync |
| Primary Purpose | Active Directory–to–Active Directory synchronization | On-prem Active Directory to Microsoft Entra ID synchronization |
| Sync Direction | AD → AD (bi-directional or uni-directional, configurable) | AD → Entra ID |
| Forest-to-Forest AD Sync | ✅ Supported | ❌ Not supported |
| Trustless Multi-Forest Sync | ✅ Supported (no domain trust required) | ❌ Not supported |
| On-Premise-Only Operation | ✅ Fully on-premise | ❌ Requires Microsoft Entra ID |
| Private Cloud (IaaS) Support | ✅ Supported (AD in Azure IaaS, AWS, private DCs) | ⚠️ Supported only as source directories for Entra ID |
| Multi-Cloud AD Parity | ✅ Supported | ❌ Not supported |
| Dependency on External Identity Platform | ❌ None | ✅ Microsoft Entra ID required |
| Password Synchronization | ✅ Real-time AD-to-AD password parity | ✅ AD-to-Entra ID password hash sync |
| Single Sign-On (SSO) | ❌ Not an SSO provider | ⚠️ Enables SSO via Entra ID |
| Attribute-Level Filtering | ✅ Supported | ✅ Supported |
| OU-Level Scoping | ✅ Supported | ✅ Supported |
| Directional Sync Control | ✅ Full control | ⚠️ Limited (cloud-centric) |
| Multi-Tenant / Hosted Environments | ✅ Designed for MSPs and hosted models | ❌ Not designed for tenant isolation |
| Use During AD Migrations | ✅ Live parallel synchronization | ❌ Limited migration support |
| Reliance on Domain Trusts | ❌ Not required | ❌ Not applicable |
| Best Fit Use Cases | M&A, AD consolidation, private cloud, regulated environments, multi-forest sync | Microsoft 365, Entra ID–centric identity models |
When MachSync Is the Better Choice
MachSync is a better fit when organizations need direct Active Directory synchronization without relying on cloud identity platforms.
Common scenarios include:
- Synchronizing identities between multiple AD forests
- Avoiding domain or forest trusts due to security concerns
- Running identity services in private or restricted environments
- Managing identities across AWS, Azure IaaS, and on-premise data centers
- Supporting mergers, acquisitions, or long-term coexistence
- Operating MSP or hosted Active Directory platforms
When Microsoft Entra ID Sync Makes Sense
Microsoft Entra ID Sync is the right choice when the goal is to:
- Connect on-premise Active Directory to Microsoft 365
- Enable cloud-based authentication and SSO
- Centralize identity in Microsoft Entra ID
- Operate in a cloud-first identity model
It works well when Entra ID is the primary identity platform and there is no need for direct forest-to-forest synchronization.
Can MachSync and Entra ID Sync Be Used Together?
Yes. In some environments, MachSync and Entra ID Sync are used side by side.
For example:
- MachSync keeps multiple AD forests aligned
- Entra ID Sync publishes identities from one selected forest to Microsoft Entra ID
This approach allows organizations to maintain internal AD consistency while still supporting Microsoft 365 and cloud services.
Key Takeaway
MachSync and Microsoft Entra ID Sync are not competing tools in the same category. They serve different identity models.
- Choose MachSync when you need secure, trustless, forest-to-forest Active Directory synchronization.
- Choose Microsoft Entra ID Sync when your goal is to integrate on-premise Active Directory with Microsoft Entra ID and Microsoft 365.
Understanding this difference helps avoid design mistakes and ensures the identity platform matches real operational needs.
Still Not Sure Which Sync Approach Fits You? Our certified and Experienced technology experts are available to answer all your questions. Contact MachSol Today.