DNS on Windows Server 2003, 3rd Edition

Creating a Subdomain in the Parent’s Zone

You can create a subdomain without delegating it, however. How? By creating resource records that refer to the subdomain within the parent’s zone.

Say one day a group of students approaches us, asking for a DNS entry for a web server for student home pages. The name they’d like is www.students.movie.edu. You might think that we’d need to create a new zone, students.movie.edu, and delegate to it from the movie.edu zone. Well, that’s one way to do it, but it’s easier to create an A record for www.students.movie.edu in the movie.edu zone. We find that few people realize this is perfectly legal. You don’t need a new zone for each new level in the namespace. A new zone would make sense if the students were going to run students.movie.edu by themselves and wanted to administer their own name servers. But they just want one A record, so creating a whole new zone is more work than necessary.

It’s easy to add this record with the DNS console. First create a students.movie.edu subdomain in the movie.edu zone, then add the www.students.movie.edu A record. To create the subdomain, right-click on the zone in the left pane and select New Domain. You’ll see a window like the one shown in Figure 10-1.

Figure 10-1. Creating a subdomain in a zone

Enter the name of the new subdomain. You don’t need to append movie.edu—the DNS console knows what you mean. You’ll ...