Re: gethostbyaddr returning null for CNAME records

From: Barry Margolin (barmar_at_alum.mit.edu)
Date: 02/26/04

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    Date: Thu, 26 Feb 2004 13:16:58 -0500

    In article <e02389e6.0402260903.4b04e3f6@posting.google.com>,
     neil@JAMMConsulting.com (Neil Aggarwal) wrote:

    > Barry:
    >
    > Let me try to understand what is happening here:
    >
    > dig -x 64.61.26.100
    > gives me a CNAME record of 100.jfax.com.
    >
    > So, I look up 100.jfax.com with this query:
    >
    > dig 100.jfax.com any
    >
    > I get no answers. Is that why the gethostbyaddr is failing?

    Yes.

    > I expected it to return 100.jfax.com

    Why would you expect that, if there's no such record?

    A CNAME record is an alias. It means "the name you asked for doesn't
    have any records of its own, look up the records attached to the
    following records instead".

    As an analogy, a CNAME record is like a Unix symbolic link. If the link
    points to a nonexistent filename, trying to open the link fails -- it
    doesn't treat the name that it points to as the "contents" of the file. 

    -- 
Barry Margolin, barmar@alum.mit.edu
Arlington, MA
*** PLEASE post questions in newsgroups, not directly to me ***
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