The Netlogon.dns file is created in the %systemroot%\System32\config folder whenever you create an Active Directory domain controller. It contains all the records needed to register the resource records of the domain controller. Netlogon.dns is used by the Windows 2003 NetLogon service and to support Active Directory for non-Windows 2003 DNS servers.
If you are using a DNS server that supports the SRV resource record but does not support dynamic updates (such as a UNIX-based DNS server or a Windows NT Server 4.0 DNS server), you can import the records in Netlogon.dns into the appropriate primary zone file to manually configure the primary zone on that server to support Active Directory.
This was first published in April 2004