Using dsquery to find the domain controllers in the domain or forest

To find all the domain controllers in the forest with DN and RDN:

    DsQuery Server -o rdn -Forest
    DsQuery Server -Forest

To find all the domain controllers in a domain:
  DsQuery Server -domain domain_name.com

To list all the domain controllers in a domain that are also Global Catalog Servers:
   DsQuery Server -domain domain_name.com -isgc

To list the domain controller in the forest that holds the Schema FSMO:
DsQuery Server -Forest -hasfsmo schema