“The time has come,” the Walrus said, “To talk of many things: Of shoes—and ships—and sealing-wax—Of cabbages—and kings—And why the sea is boiling hot—And whether pigs have wings.”
It’s time we tied up loose ends. We’ve already covered the mainstream of DNS, but we haven’t explored a handful of interesting niches. Some of these, like instructions on how to set up DNS on a network without Internet connectivity, may actually be useful; others may just be interesting. We can’t in good conscience send you out into the world without completing your education!
We talked about CNAME resource records in Chapter 4. We didn’t tell you all about CNAME records, though; we saved that for this chapter. When you set up your first name servers, you didn’t care about the subtle nuances of the magical CNAME record. Maybe you didn’t realize there was more to it than we explained; maybe you didn’t care. Some of this trivia is interesting, some is arcane. We’ll let you decide which is which.
If you’ve ever renamed your zone because of a company reorganization, you may have considered creating a single CNAME record that pointed from the zone’s old domain name to the new domain name. For instance, if the fx.movie.edu zone were renamed to magic.movie.edu, we’d be tempted to create a single CNAME record to map all the old names to the new names:
fx.movie.edu. IN CNAME magic.movie.edu.
With this record in place, you’d expect a ...