Use netdom to find where the current FSMO roles are assigned in Active Directory:

netdom query fsmo

This will return something like:

Schema master               DC01.local
Domain naming master        DC02.local
PDC                         DC01.local
RID pool manager            DC02.local
Infrastructure master       DC01.local

The command completed successfully.

The ‘netdom query’ command can also return other useful information. Valid types include:

Server, Workstation, DC, OU and Trust