Fortinac LDAP and RADIUS

Hi, 

You can use Winbind but keep in mind that Winbind is used to provide MSCHAPv2 authentication only. If using a different scheme, such as EAP-TTLS/PAP or EAP-TLS, configuration is not required.

More information can be found here https://docs.fortinet.com/document/fortinac-f/7.6.0/administration-guide/670285/winbind

I hope this will be helpful. 

Regards

Winbind is a tool used to validate the challenges for authentication types that don't exchange passwords (emulate a windows PC) like MSCHAPv2, some details are shown in this article.
FNAC has Winbind included in its local RADIUS server that can be used to replace Windows NPS server roles and also offer advanced NAC features.