NetApp
Configuration > Protocols > CIFS : Monitoriing CIFS : Resetting CIFS domain controllers

Resetting CIFS domain controllers
You have to update the storage system’s available domain controller discovery information after you add or delete a domain from the list of preferred domain controllers. You have to reset the CIFS connection to domain controllers for the specified domain . Failure to reset the domain controller information can cause a connection failure.
Steps 
1.
From the Home tab, double-click the appropriate storage system.
2.
 Configuration > Protocols > CIFS.
3.
In the Domain tab, click Reset.