A record of domain name must be name server ?

Matus UHLAR - fantomas uhlar at fantomas.sk
Thu Sep 11 16:08:06 UTC 2014

>On 9/11/2014 3:47 AM, Matus UHLAR - fantomas wrote:
>>On 10.09.14 18:13, Kevin Darcy wrote:
>>>No, what I'm saying is that if
>>>example.com owns an A record, and
>>>www.example.com owns an A record, then
>>>where does point?
>>Completely your decision.
>>>Some people will point it at example.com, some will point it at 
>>>www.example.com. What you get is a mish-mosh. No consistency.
>>Do not mix multiple A and PTR. they are just different things.
>>You are creating issues where there are none.

On 11.09.14 11:20, Kevin Darcy wrote:
>The issue is consistency. If you give admins choices where to point a 
>PTR, and the RFCs don't provide any clear guidance, you're going to 
>get inconsistent results.

sorry, but again - you are searching for consistency somewhere, where no
consistency (nor a PTR) is required.

>Consistency is a good thing, isn't it? Sure, the earth isn't going to 
>fall off its axis of rotation just because of the way people point 
>their A and PTR records, CNAME or don't CNAME. But if we can nudge 
>people in the direction of consistency, and there is no downside, why 
>wouldn't we do that? That's what "best practices" are all about -- 
>impelling people towards processes/methods/conventions that 
>ultimately benefit *everyone*. Greatest good for the greatest number, 
>and all that.

I haven't met a case where this level of "consistency" would be needed.
I have met a case where the "only one A should point to an IP" caused

your argument fails immediately when there's need for more than just A on

>(Yes, I'm aware that there was a proposal recently discussed on the 
>DNSOP list for an MX-target convention to denote "no mail service 
>offered here". That would presumably solve the problem I cited in the 
>previous paragraph. But AFAIK that proposal is many years away from 
>widespread adoption, and even if adopted, it puts an extra burden on 
>the DNS admins to populate the "no service" MX record, which, again, 
>is going to produce inconsistent results -- some admins will remember 
>to do it; many won't).

... and this is just example of it.

>>The same applies for all other RRs for exmaple.com Alan named crap.
>Actually, the only other RR type that Alan enumerated specifically 
>was NS, which operates on entirely different principles, and serves a 
>significantly different function, than MX-based mail routing. Who 
>would be looking up www.example.com with QTYPE=NS? Is that even a 
>plausible use-case scenario?

well, me and Alan have shown examples why "www CNAME @" is not a good idea.
we both also said it's personal preference.

>What other RR types do you have in mind? 

Does it matter at all? It _may_ happen, and it's the case where CNAME is
not usable.

Matus UHLAR - fantomas, uhlar at fantomas.sk ; http://www.fantomas.sk/
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