Azure AD Join (Entra Join) vs Hybrid Azure AD Join vs Azure AD Registration (Workplace Join)

Hi lfk73​ , check this

Azure AD Registration (Workplace Join) — for BYOD

Security Concerns: Why allow this?

You're right — letting users register their personal laptops or phones can open the door to unmanaged, potentially insecure endpoints.

Why organizations might still use it:

1. Access from anywhere: Users might need access to web-based resources (like Outlook or SharePoint) from their personal devices.
2. Conditional Access: You can enforce MFA, device compliance, limited access (e.g., no downloads) even on these registered devices.
3. Self-service password reset, SSO, and device-based Conditional Access become available.

How to manage security:

• Use Conditional Access to restrict what registered devices can access (e.g., block access to sensitive apps).
• Use Microsoft Defender for Endpoint to detect risky behavior.
• Use compliance policies (e.g., block jailbroken phones, require PINs).

If you're strict on device control, you can disable self-registration and require only joined (not just registered) devices.

Hybrid Azure AD Join — for hybrid environments

Used when:

• Devices are joined to on-prem AD for legacy apps/file shares.
• You also want them visible and manageable in Entra ID for cloud apps.

Use Case:

• Authenticate to on-prem resources with Kerberos/NTLM.
• Use cloud features (SSO to M365, Conditional Access, etc.)

It’s the default for enterprises with existing AD environments.

Azure AD Join (Entra Join) — Cloud-native devices

Used when:

• You have cloud-first devices (e.g., autopilot-deployed Windows 11 laptops).
• Users sign in using Entra credentials only — no on-prem domain join.

What about access to on-prem resources?

• By default, Azure AD Joined devices can't directly access:
• File shares
• Print servers
• Apps using Kerberos/NTLM or AD-integrated security

Unless you:

• Have line-of-sight to a domain controller (via VPN).
• Use Azure AD Kerberos (newish feature) for things like Windows Hello or file shares.
• Implement Hybrid Identity tools like Azure AD App Proxy for legacy app publishing.

So if your users need access to both on-prem and cloud resources, and your infra is not fully cloud-migrated yet:

Hybrid Azure AD Join is usually required.

TL;DR – Which to use when?

Final Guidance

• Don’t allow Azure AD Registration freely unless you layer in strong Conditional Access policies.
• If you need both on-prem and cloud app access, Hybrid Azure AD Join is your best bet.
• If moving toward full cloud-native infra, Entra Join (Azure AD Join) is the future — but legacy app support must be addressed.