Skip to main content
NetApp Knowledge Base

Clients using NTLM when Kerberos is expected in ONTAP

  1. Last updated
  2. Save as PDF
Views:
6,635
Visibility:
Public
Votes:
1
Category:
ontap-9
Specialty:
nas
Last Updated:

Applies to

  • ONTAP 9 (all versions)
  • CIFS / SMB
  • Windows Active Directory with Kerberos authentication
  • AFF / FAS systems

Issue

Clients are using authentication style NTLM when Kerberos is expected. This includes the following scenarios:

  • A client-side packet trace shows KRB5KDC_ERR_S_PRINCIPAL_UNKNOWN
  • Windows clients receive access failures after Group Policy Object (GPO) is configured to block NTLM and enforce Kerberos authentication
  • klist on the Windows client shows no Kerberos ticket is obtained for the CIFS server
  • Event Viewer logs NTLM fallback blocked or Kerberos negotiation failure events for the NetApp CIFS server
  • Network drive mappings continue failing even after SPN-related GPO changes are applied

Sign in to view the entire content of this KB article.

New to NetApp?

Learn more about our award-winning Support

NetApp provides no representations or warranties regarding the accuracy or reliability or serviceability of any information or recommendations provided in this publication or with respect to any results that may be obtained by the use of the information or observance of any recommendations provided herein. The information in this document is distributed AS IS and the use of this information or the implementation of any recommendations or techniques herein is a customer's responsibility and depends on the customer's ability to evaluate and integrate them into the customer's operational environment. This document and the information contained herein may be used solely in connection with the NetApp products discussed in this document.