How To Fix LDAP016 - Authentication mechanism &1 is unknown

SAP Error Message - Details

• Message type: E = Error

• Message class: LDAP - LDAP Interface Messages in ABAP

• Message number: 016

• Message text: Authentication mechanism &1 is unknown

What causes this issue?

You want to log on to a directory server with the authenticaton method
&V1&. However, this authentication method is not supported.

System Response

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

How to fix this error?

If you want to log on with an LDAP system user (Viewcluster VC_LDAP,
maintain <LS>Server</>, field <LS>System logon</>), ensure that the
field <LS>Auth. Mechanism</> (in LDAPUSER view) contains a valid value
(input help).
If you are not using a system user, it is possible that a program error
has occurred.

Procedure for System Administrators

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message LDAP016 - Authentication mechanism &1 is unknown ?

  The SAP error message LDAP016 indicates that there is an issue with the authentication mechanism specified in the LDAP (Lightweight Directory Access Protocol) configuration. The message typically states that the authentication mechanism you are trying to use is not recognized or is not supported by the system.
  Cause
  The error can occur due to several reasons:
  
  Incorrect Configuration: The authentication mechanism specified in the LDAP configuration is incorrect or misspelled.
  Unsupported Mechanism: The specified authentication mechanism is not supported by the version of SAP or the LDAP server you are using.
  Missing Libraries: Required libraries or components for the specified authentication mechanism may not be installed or configured properly.
  Version Mismatch: There may be a mismatch between the SAP system and the LDAP server regarding supported authentication methods.
  
  Solution
  To resolve the LDAP016 error, you can follow these steps:
  
  
  Check Configuration:
  
  Go to the SAP system and check the LDAP configuration settings. Ensure that the authentication mechanism specified is correct and supported.
  You can check the configuration in transaction SU01 (User Maintenance) or SICF (HTTP Service Hierarchy Maintenance) depending on where the LDAP settings are configured.
  
  
  
  Supported Mechanisms:
  
  Verify the list of supported authentication mechanisms for both your SAP system and the LDAP server. Common mechanisms include simple, SASL, GSSAPI, etc.
  Ensure that the mechanism you are trying to use is indeed supported by both systems.
  
  
  
  Update Libraries:
  
  If you are using a specific authentication mechanism that requires additional libraries (like SASL), ensure that those libraries are installed and properly configured on the server.
  
  
  
  Check Documentation:
  
  Refer to the SAP documentation or the LDAP server documentation for guidance on supported authentication mechanisms and configuration examples.
  
  
  
  Test Connection:
  
  Use tools or commands to test the LDAP connection and authentication outside of SAP to ensure that the LDAP server is functioning correctly.
  
  
  
  Consult SAP Notes:
  
  Check the SAP Support Portal for any relevant SAP Notes that might address this specific error or provide additional troubleshooting steps.
  
  
  
  Contact Support:
  
  If the issue persists after checking the above points, consider reaching out to SAP support for further assistance.
  
  
  
  Related Information
  
  SAP Documentation: Review the official SAP documentation for LDAP integration and authentication mechanisms.
  LDAP Server Documentation: Check the documentation for your specific LDAP server (e.g., Active Directory, OpenLDAP) for details on supported authentication methods.
  SAP Community: Engage with the SAP Community forums to see if others have encountered and resolved similar issues.
  
  By following these steps, you should be able to identify and resolve the cause of the LDAP016 error in your SAP system.