DSfW uses the Novell DNS service as its location service, enabling users or computers to find the location of network resources. DNS maps hostnames to IP addresses and locates the services provided by the domain, such as LDAP, Kerberos and Global Catalog.
For more information on working of DNS with DSfW, see Understanding DNS in Relation to DSfW
in the OES 2 SP3: Domain Services for Windows Administration Guide.