You have the ability to use local accounts built into the Nutanix UI or use or use Active Directory.You can also you use Common Access Card (CAC) but that is out of the scope of this post.
The URL format is as follows for an LDAP entry (the only entry supported currently): ldap://host:ldap_port#. The host value is either the IP address or fully qualified domain name. The default LDAP port number is 389.
Directory Type: Select Active Directory from the pull-down list.
Active Directory (AD) is a directory service implemented by Microsoft for Windows domain networks. It is the only option available currently.
Enable the Active Directory Service
Add Active Directory Mapping
You do have to use the NCLI to create a Active Directory Mapping for roles in NOS 3.5.2. You can use groups or use a 1 to 1 mapping for your active directory users.
ncli> authconfig add-role-mapping name=dalab role=ROLE_CLUSTER_ADMIN type=USER values=administrator
Directory Name : dalab
Role : ROLE_CLUSTER_ADMIN
Entity Type : USER
Entity Values : administrator