Error Message

A review of the CIFS log file reveals the following:

Date time zone [cifs.servername.infoMsg:info]: CIFS: Warning for server \\FILESERVERNAME: Connection terminated.
Date time zone [cifs.servername:smbrpc.exceptionCaught:error]: CIFSRPC: An RPC exception with a server of type file policy server occurred.
Date time zone [cifs.servername:fpolicy.fscreen.server.requestError:error]: FPOLICY: An attempt to make a file screen request to server \\FILESERVERNAME for policy ev-placeholder failed with error [0xc0020052].
 

Windows clients negotiate SMB signing by default if it is enabled on the Windows server. In this case they could fail because CIFS communications is encountering SMB signing on the Windows Servers but not on the NetApp device.

1. If you do not require SMB protection against replay attacks for your Windows clients and servers, then disable SMB Signing on all Windows systems communicating with the NetApp device

2. If you do require SMB protection against replay attacks for your Windows clients and servers, then enable SMB Signing on all Windows systems and on the NetApp device


To enable or disable SMB Signing on Windows:
1. Open the Registry Editor (regedit.exe)
2. Navigate to the key HKLM/SYSTEM/CurrentControlSet/Services/LanManServer/Parameters
3. Modify or create the following two DWORD entries:  RequireSecuritySignature and EnableSecuritySignature
4. Set both values to 1 to enable SMB Signing. Set both values to 0 to disable SMB Signing.

Warning: Incorrect use of the Windows registry editor may prevent the operating system from functioning properly. Great care should be taken when making changes to a Windows registry. Registry modifications should only be carried-out by persons experienced in the use of the registry editor application. It is recommended that a complete backup of the registry and workstation be made prior to making any registry changes.

For more information on SMB Signing for Windows, contact Microsoft Support or see:
https://msdn.microsoft.com/en-us/library/aa302188.aspx 
https://support.microsoft.com/kb/887429


To enable or disable SMB Signing on NetApp devices:
1.Turn on the option cifs.signing.enable on
Note: SMB signing is disabled by default on the NetApp storage system for performance reasons.