reverse look-up oddity

[Barry Margolin]

In article <9j6rc8$2nq at pub3.rc.vix.com>,
mark <random_soul at mailandnews.com> wrote:
>
>I recently started a new job, and have been given the task of
>cleaning-up DNS. Currently reverse look-ups are returning this for the
>server info:
>
>Server:  host.IN-ADDR.ARPA
>
>And all of the PTR records in the domain.rev file are suffixed with
>.IN-ADDR.ARPA instead of the domain name.  I cannot find anything in
>the new O'Reilly book, in the archives for this newsgroup or in the
>DNS FAQ on the web that address this (sorry for the pun!).
>
>The only thing that stands out is that the hostname for the box is not
>fully qualified, but would that be referenced on a reverse look-up?

If you don't put a "." at the end of a hostname in a zone file, the $ORIGIN
(which defaults to the zone name) is automatically appended.  This happens
regardless of whether it's a forward or reverse zone file.  PTR records
should look like:

123 IN PTR hostname.domain.

rather than

123 IN PTR hostname

-- 
Barry Margolin, barmar at genuity.net
Genuity, Burlington, MA
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