Query and Update DNS

As the naming service for the Internet, DNS is a crucial infrastructure in all enterprises, large and small. DNS has been around for more than 15 years and was first defined as part of Internet Engineering Task Force (IETF) Request for Comments (RFC) 1034 and RFC 1035 and later updated in RFC 2181. Microsoft finally moved from its proprietary WINS to DNS with the introduction of Active Directory (AD).

AD uses DNS as part of the service locator process. When a Windows-based client attempts to contact a domain controller (DC), Global Catalog (GC) server, or Kerberos Key Distribution Center (KDC), AD queries DNS in the background to find the most optimal server to use. If you understand how entries, or Resource Records (RRs), are structured in DNS and the basics of how to use the Perl Net::DNS modules, you can write scripts and applications to perform functions such as finding all the DCs in a site or domain, finding all the GC servers in a forest, and updating DNS when you bring new servers online. . . .