Re: [DNSOP] I-D Action: draft-ietf-dnsop-attrleaf-06.txt

[Dave Crocker <[e-mail]>]

On 3/29/2018 10:30 AM, Paul Vixie wrote:
> since the _ was chosen as nonconflicting, and since you desire to 
> explain what it is we aren't conflicting with, and since the RFC 1035 
> language is both non-normative and archaic by inspection, i really think 
> that 952 is the correct, and only correct, reference to use.

Thanks for the detailed explication.  I think it's odd to have a DNS 
naming-related discussion that does not cite either of the seminal 
standards documents for domain naming, but I suppose there's isn't much 
downside at this place in the document, to cite only RFC 952.


> as a side node, RFC 952 permits host names of only 24 characters or 
> less, including those which have interior periods for RFC 921 purposes. 
> therefore, a protocol lawyer could say that any name longer than 24 
> characters, or beginning with a number, was by definition 
> non-conflicting with RFC 952, and needs no underscore to achieve same. i 
> do not harbor this view, and i believe that the LEXICAL GRAMMAR section 
> is more definitional than the ASSUMPTIONS section of RFC 952.

To me, that's an example of the problem with citing only that document: 
It is not definitive on 'host name'.  That RFC 1035 isn't, really, 
either was my reason for wanting to cite both.  But anyhow, the next 
version will have only 952.


>> Trying to eliminate the issue entirely, is this sufficient:
>>
>> <section title="Scaling Benefits">
>>
>> <t>Some resource record types are used in a fashion that can create
>> scaling problems, if an entire RRset associated with a domain name is
>> aggregated in the leaf node for that name. An increasingly-popular
>> approach, with excellent scaling properties, places the RR under a
>> node having an underscore-based name, at a defined place in the DNS
>> tree under the 'parent' name. This constrains the use of particular
>> <spanx style="verb">RR</spanx> types associated with that parent
>> name. A direct lookup to the subordinate leaf node produces only the
>> desired record types, at no greater cost than a typical DNS
>> lookup.</t>
>>
>> <t>The definition of a underscore global registry, provided in this
>> specification, primarily attends to the top-most names used for
>> coping an RR type; that is the _underscore "global" names. </t>
>>
>> </section>
> 
> it's almost 100% of the way there. but, you should say "places the 
> RRset"

oops.  quite correct.


>>>>> in: 2. DNS Underscore Scoped Entry Registries Function
>>>> ...
>>>>> /name space/name space, just as every RR type owns a distinct,
>>>>> subordinate name space./
>>>>
>>>> An RR type owns a name space? I don't understand what that means or how
>>>> it is correct.
>>
>> While I think I see a computer science basis for saying that an RR type
>> has a namespace, I'm continuing to find the point more confusing than
>> helpful, and fear that other readers will, too.
>>
>> At the least, can you point me to official documents that explain that
>> view? I've looked around a bit an haven't found such a specification or
>> discussion.
> 
> it only contains a namespace for the purposes of your underscore 
> registry. no use of _TCP by any other RR type will conflict with the use 
> of _TCP by SRV, for example. thus, each RR type effectively has its own 
> registry, whose names need only be unique within that registry. you may 
> prefer to call it a dictionary rather than a namespace in order to avoid 
> confusion around what other DNS RFC's call a "namespace".

Oh.  Alas, I'm still not seeing how this is helpful pedagogy for the 
average reader.  Let's suspend this until the next version and see how 
the doc sits with folks.

d/


-- 
Dave Crocker
Brandenburg InternetWorking
bbiw.net