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

Wed Oct 17 19:41:24 UTC 2012

On Wed, Oct 17, 2012 at 12:25:49PM -0700, Landon Stewart wrote:
> 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? 

"You should remove the one that you don't need."  A CNAME may not be
at the same owner name as any other RR.  If you need an alias, then
you want a CNAME.  If you need some other record, you need not to have
a CNAME.

If you think about what a CNAME is, it is obvious that it can't exist
at the same name as any other RR, because it says "this name is
actually that name over there".

> Should the CNAME just get nuked in all of these cases?

Probably.

A

-- 
Andrew Sullivan
Dyn Labs
asullivan at dyn.com