Finding the PDC Emulator FSMO Role Owner via DNS
You want to find the PDC Emulator for a domain using DNS.
Using a command-line interface
> nslookup -type=SRV _ldap._tcp.pdc._msdcs.<DomainDNSName>
The PDC Emulator FSMO role is the only FSMO role that is stored in DNS. Like many of the other Active Directory-related DNS records, the PDC record is stored as an SRV record under _ldap._tcp.pdc._msdcs.<DomainDNSName> where <DomainDNSName> is the domain the PDC is in. This allows your Active Directory clients to use normal DNS name resolution to locate the PDC Emulator for their domain.
Recipe 3.26 for finding domain controllers via DNS