Thanks. Netapp support advised me if "is-nbns-enabled" is FALSE then NetBiOS cannot be in use on the SVM. So even if
is-netbios-over-tcp-enabled is True given that the other setting is FALSE then NetBIOS cannot be in use.
However, I have found the above isn't the case. I still see NetBios being used:
vserver cifs session show -instance -node * -vserver SVM1 -protocol-version *
EG: Session ID: 9569304783xxxxxxxxx
Connection ID: 3725xxxxxx
Incoming Data LIF IP Address: 172.24.xx.xx
Workstation IP Address: 10.xx.xx.xx
Authentication Mechanism: Kerberos
User Authenticated as: domain-user
..
NetBIOS Name: xxxxxxxxxx
If anyone can help - much appreciated.