- **LDAP Authentication/Queries** β Applications can have LDAP server settings pointing to AD and perform binds or lookups, custom-developed or third-party products prompting users for AD credentials.
- **Federation/Modern Authentication** β Some applications are already federated via AD FS, or support modern protocols such as SAML or OAuth. These can generally be reconfigured to use Microsoft Entra ID with minimal effort.
- **Other Legacy Methods** β Includes cases where apps use RADIUS against AD or local accounts. Though not the primary focus, these should be documented for completeness.
### Step 3. Assess modernization feasibility
### Step 7. Handling LDAP-based applications (Directory-Bound Apps)
**LDAP-bound applications** or services directly query Active Directory Domain Services (AD DS) via LDAP, most often for authentication using a simple bind with username and password, or for directory reads. Common examples include older enterprise applications, network appliances, or custom-developed apps that rely on LDAP binds to validate credentials. These applications typically require an LDAP server, and can't easily transition to modern authentication protocols.
#### Recommended Solution: Microsoft Entra Domain Services
The recommended solution for supporting LDAP-bound apps in the cloud is Microsoft Entra Domain Services. Hosted on Azure, Microsoft Entra Domain Services provides LDAP, Kerberos, and NTLM endpoints, syncing user accounts, and credentials from your Microsoft Entra ID tenant. This allows legacy applications to use cloud-hosted AD for authentication without switching
to modern protocols. The managed domain mainly supports read and authentication for LDAP clients.
### Step 8. Handling Kerberos-Based Applications (Windows Integrated Auth)
- **LDAP Authentication/Queries** β Applications can have LDAP server settings pointing to AD and perform binds or lookups, custom-developed or third-party products prompting users for AD credentials.
- **Federation/Modern Authentication** β Some applications are already federated via [AD FS](/windows-server/identity/ad-fs/ad-fs-overview), or support modern protocols such as SAML or OAuth. These can generally be reconfigured to use Microsoft Entra ID with minimal effort.
- **Other Legacy Methods** β Includes cases where apps use RADIUS against AD or local accounts. Though not the primary focus, these should be documented for completeness. For more information, see: [RADIUS authentication with Microsoft Entra ID](../../architecture/auth-radius.md).
### Step 3. Assess modernization feasibility
### Step 7. Handling LDAP-based applications (Directory-Bound Apps)
**LDAP-bound applications** or services directly query Active Directory Domain Services (AD DS) via LDAP, most often for authentication using a simple bind with username and password, or for directory reads. Common examples include older enterprise applications, network appliances, or custom-developed apps that rely on LDAP binds to validate credentials. These applications typically require an LDAP server, and can't easily transition to modern authentication protocols. For more information, see: [LDAP authentication with Microsoft Entra ID](../../architecture/auth-ldap.md).
#### Recommended Solution: Microsoft Entra Domain Services
The recommended solution for supporting LDAP-bound apps in the cloud is Microsoft Entra Domain Services. Hosted on Azure, Microsoft Entra Domain Services provides LDAP, Kerberos, and NTLM endpoints, syncing user accounts, and credentials from your Microsoft Entra ID tenant. This allows legacy applications to use cloud-hosted AD for authentication without switching
to modern protocols. The managed domain mainly supports read and authentication for LDAP clients. For more information, see: [What is Microsoft Entra Domain Services?](../../identity/domain-services/overview.md).
### Step 8. Handling Kerberos-Based Applications (Windows Integrated Auth)