Applies to ONTAP CIFS Answer Firewall on AD should open port 445 bi-directionally which is needed for SMB/CIFS to work properly and ensure that the server is listening on port 445 and that no firewall...Applies to ONTAP CIFS Answer Firewall on AD should open port 445 bi-directionally which is needed for SMB/CIFS to work properly and ensure that the server is listening on port 445 and that no firewalls (or other network devices) are blocking communication between ONTAP and the Domain Controllers.