DNS hostnames with a duplicate CNAME and A record - which should be removed?

William Herrin bill at herrin.us
Wed Oct 17 20:00:49 UTC 2012


On Wed, Oct 17, 2012 at 3:25 PM, Landon Stewart <lstewart at superb.net> wrote:
> The problem is that we have some zones that have records with the same
> hostname that have both a CNAME as well as an A record, MX record, SOA
> record and/or NS record.  Is there an easy answer for what should be
> removed?  I'm inclined to say that the CNAME should be removed in all these
> cases but I can't find any definitive information on this and after doing
> some tests it doesn't always seem straightforward.

If you have a CNAME record for a particular name, you should not have
any other record of any type for that same name. Which you should
remove depends on the details of the particular circumstance. If you
really mean "identical to that other name with respect to all records
and record types" then there's nothing inherently wrong with the
CNAME. If you don't, then you shouldn't use a CNAME there.

Regards,
Bill Herrin


-- 
William D. Herrin ................ herrin at dirtside.com  bill at herrin.us
3005 Crane Dr. ...................... Web: <http://bill.herrin.us/>
Falls Church, VA 22042-3004



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