Is my DNS set up properly for reverse lookups?

[Barry Margolin]

In article <930331427.776.48 at news.remarQ.com>,
Tim Lanza <Tim at Lanzahost.com> wrote:
>Thank you, Barry, I really appreciate the assistance.  Please pardon one
>last request...  OK, so PTR records can be listed for multiple domains.  My
>single reverse zone file looks like this:
>
>@       IN      SOA     firstdomain.com. hostmaster.firstdomain.com.  (
>                                      1999050900 ; Serial
>                                      8H      ; Refresh
>                                      2H      ; Retry
>                                      1W      ; Expire
>                                      1D )    ; Minimum
> NS foo.firstdomain.com.
>444 PTR foo.firstdomain.com.
>444 PTR www.firstdomain.com.
>
>If, as you suggest that this is potentially confusing, is there a better way
>to do this?

Pick one name and put it in the PTR record.

Also, is there a reason why both foo.firstdomain.com and
www.firstdomain.com are A records?  Why not make www be a CNAME in the
forward domain?  Then you won't feel the need for a PTR record.

>The SOA statement in this file references only firstdomain.com.  Is that a
>problem?

Nothing currently uses the information in the SOA record.  However, I'm not
sure what problem you think it might be.  The first field in the SOA record
is the hostname of the primary master server for the domain.

>What is the impact of just deleting the reverse lookup record for
>seconddomain?

When someone translates 111.222.333.444 to a name they won't get
www.seconddomain.com.

>And, how can I test the reverse lookups?

dig -x 111.222.333.444 ptr

-- 
Barry Margolin, barmar at bbnplanet.com
GTE Internetworking, Powered by BBN, Burlington, MA
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