need some help

[Jim Reid]

>>>>> "hannah" == hoyoung  <hoyoung at us.ibm.com> writes:

    >> You're safer to make the
    >> entry in your zone file a CNAME for the corresponding name in it's
    >> real domain. ie:
    >> dublin.mayo.rock.edu. IN CNAME public.nash.rock.edu.

    hannah> But since I don't own the domain, don't I need to have the
    hannah> admin of the domain to enter a RR in their domain, too?

Well, yes. But then you did say that the host dublin.mayo.rock.edu was
going to be moved to public.nash.rock.edu. That's not going to happen
unless the nash.rock.edu zone gets updated... :-) Once that update is
done, you just add the CNAME to your zone to preserve backwards
compatibility for the things which use the old name for the host.

BTW, dangling CNAMEs - CNAMEs which point at some non-existent RR -
are legal, though they obviously aren't much use. There's not much
point in having a CNAME point into empty space.