While troubleshooting client access issues to a CIFS share, you notice that the issue only occurs when the data LIF that the clients are accessing is…

The problem is isolated to a specific node when it hosts the CIFS data LIF. This indicates a node-specific configuration or state issue rather than a cluster-wide or SVM-wide problem. CIFS authentication, particularly Kerberos, is a primary candidate. Kerberos is time-sensitive and requires that the clock on the storage node be synchronized with the Key Distribution Center (KDC), which is typically a domain controller. If a single node has a significant clock skew or a broken secure channel to the domain controller, Kerberos authentication will fail for any client connections landing on a LIF hosted by that node.

A. cluster health: A general cluster health problem would likely manifest as a more widespread or intermittent issue, not one consistently tied to a specific node hosting a LIF.

C. share path: The share path is a storage virtual machine (SVM) level configuration. An incorrect share path would cause access to fail regardless of which node's LIF the client connects through.

D. export policies: Export policies are used to control access for the NFS protocol. CIFS access is controlled by share-level permissions and NTFS file-level permissions.

1. NetApp ONTAP 9 Documentation

SMB/CIFS management

"Troubleshoot SMB server and domain issues": This guide details common SMB issues

including "Authentication failures due to time skew." It states

"Kerberos authentication can fail if the time difference between the cluster and the Windows domain controller that is acting as the Kerberos Key Distribution Center (KDC) is greater than the configured maximum clock skew (the default is five minutes)." This highlights that a time issue

which can be node-specific if NTP is misconfigured on one node

will cause Kerberos failures.

2. NetApp Technical Report 4835

"SMB Protocol Best Practices with NetApp ONTAP

" Section 3.1

"Time Services": This document emphasizes the importance of time synchronization for Kerberos. It states

"Kerberos authentication is time sensitive and requires that the clocks on the client

the storage system

and the KDC are all synchronized. NetApp recommends configuring NTP on the ONTAP cluster and on the domain controllers." A failure of NTP on a single node would lead to the described scenario.

3. NetApp ONTAP 9 Documentation

SMB/CIFS management

"How Kerberos authentication works": This section explains that for Kerberos to succeed

a secure communication channel must exist between the ONTAP system and the Active Directory domain. This secure channel is established and maintained by each node that could potentially serve CIFS data

making its health a node-specific concern.