Overview#Domain Naming Master FSMO Role is a Flexible Single Master Operation and a Domain Controller responsible for making changes to the AD Forest-wide Domain Name System of the Microsoft Active Directory Configuration Directory Partition
(that is, the Partitions\Configuration naming context or LDAP://CN=Partitions, CN=Configuration, DC=<domain>).
Domain Naming Master FSMO Role Domain Controller is the only one that can add or remove a AD DOMAIN from the Microsoft Active Directory. Domain Naming Master FSMO Role can also add or remove cross references to AD DOMAINs in external AD Forest.
There is only one Domain Naming Master FSMO Role per AD Forest.