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

Landon Stewart lstewart at superb.net
Thu Oct 18 17:39:28 UTC 2012


Thanks for all your replies.

I'm going to have go through these records and resolve these issues by
evaluating them one by one since there doesn't seem to be any quick and
dirty rules to any of them.

On 18 October 2012 08:49, jeff weisberg <jaw+nanog01 at tcp4me.com> wrote:

>
> On 17 Oct 2012, at 15:25, Landon Stewart 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.
>>
>
>  # dig @ns1.superb.net +nocmd superbcolo.biz mx +noques +answer
>> ;; ANSWER SECTION:
>> superbcolo.biz. 86400 IN MX 10 superbcolo.biz.
>> superbcolo.biz. 86400 IN CNAME superbenterprise.net.
>>
>
>
>
>  Should the CNAME just get nuked in all of these cases?
>>
>
>
> no.
>
> if you nuke them, you'll break something.
>
> you're going to need to go through them all one by one, figure out
> why the CNAME is there, what it is doing, and how to change it.
>
>
> for example, "superbcolo.biz" has an MX and CNAME. the CNAME
> points to "superbenterprise.net", which has an A, and that A
> has a web server running.
>
> it may be "wrong", but http://superbcolo.biz works. so in this
> case, you'd need to replace the CNAME with the A. otherwise,
> you're breaking someone's website. which might be bad.
>
>
>
>


-- 
Landon Stewart <LStewart at Superb.Net>
Sr. Administrator
Systems Engineering
Superb Internet Corp - 888-354-6128 x 4199
Web hosting and more "Ahead of the Rest": http://www.superbhosting.net


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