topic Netbios use or not? in Network and Storage Protocols

Netbios use or not?

Roeliezzz — Wed, 04 Jun 2025 10:19:51 GMT

Hi, we are trying to eliminate use of NetBIOS in our customer DOMAINS. However, the wintel guys don't know if they use it.

After reading today I was under the impression if they use AD/DNS there is no need for NetBIOS?

If anyone can enlighten on this or have a good document that would be great - thanks.

Also I'm unclear as to what the below means: is-nbns-enabled" FALSE mean that it is off for both settings?

vserver is-netbios-over-tcp-enabled is-nbns-enabled

svm1 true false domain A

svm2 false true domain B

Re: Netbios use or not?

hmoubara — Thu, 08 Jul 2021 05:58:55 GMT

Hello,

You are correct, since you are using AD/DNS there is no need to use NetBios name service. I was not able to find some document or article for further clarification but you can check the below documentation:

https://docs.netapp.com/ontap-9/topic/com.netapp.doc.cdot-famg-cifs/GUID-16905FD4-758F-441D-A5D4-820A46EC209C.html

As for the settings ( is-netbios-over-tcp-enabled & is-nbns-enabled) is set to either false or true per vserver (svm).

In the example provided, vserver svm1 have the is-netbios-over-tcp-enabled setting set to true which is enabled and the "is-nbns-enabled" setting set to false which is mean is not enabled. The vserver svm2 has the options set the opposite.

Below command can help you change both options:

vserver cifs options modify -vserver <vserver name> -is-nbns-enabled <true/false>

vserver cifs options modify -vserver <vserver name> -is-netbios-over-tcp-enabled <true/false>

Thanks

Re: Netbios use or not?

Roeliezzz — Tue, 13 Jul 2021 13:03:55 GMT

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.