DNS on Windows Server 2003, 3rd Edition

Zone Datafile Controls

The datafiles for all name servers, whether Microsoft or BIND, can include two control entries: $ORIGIN and $INCLUDE. $ORIGIN changes the origin, and $INCLUDE inserts a new file into the current file. These control entries are not resource records; they facilitate the maintenance of DNS data. They were designed back in the “good old days” as a shortcut for people who had to edit zone datafiles by hand. If you make changes to your zones with the DNS console only, you won’t encounter these controls: the Microsoft DNS Server doesn’t use them in the zone datafiles it generates. However, some day you might need to work with zone datafiles created by hand, so it’s important that you understand these controls.