different TTLs for multiple TXT records

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different TTLs for multiple TXT records

Verne Britton-2
I see that RFC2181, written I think 20+ years ago, says in part


>
>5.2. TTLs of RRs in an RRSet
>
>   Resource Records also have a time to live (TTL).  It is possible for
>   the RRs in an RRSet to have different TTLs.  No uses for this have
>   been found that cannot be better accomplished in other ways.  This
>   can, however, cause partial replies (not marked "truncated") from a
>   caching server, where the TTLs for some but not all the RRs in the
>   RRSet have expired.
>
>   Consequently the use of differing TTLs in an RRSet is hereby
>   deprecated, the TTLs of all RRs in an RRSet must be the same.
[...]



but in the last few years, perhaps even a decade, TXT record usage has expanded to be used for many different and unique purposes, such as domain ownership verification and SPF data.


What is the proper avenue to request an enhancement so each TXT record can have its own unique TTL value?

Can bind be changed to do this, or must the RFC be changed first?


Or, please give advice on how to do this today  :-)


a live example for a client


dig TXT newriver.edu

;; ANSWER SECTION:
newriver.edu.           3590    IN      TXT     "docusign=b8923ecb-9c2e-4ead-ac43-17c3d522fd49"
newriver.edu.           3590    IN      TXT     "MS=ms76391508"


I desire to have the MS= record have a TTL of say 3600, but want the docusign record to have a TTL of 86400

... I put 3590 in there to make it easier to find it when looking at the zone file ...



Verne
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Re: different TTLs for multiple TXT records

Mark Andrews
It won’t happen and there is zero point in doing so as all RRs in a RRset are deleted at the same time.
--
Mark Andrews

> On 26 Sep 2020, at 23:59, Verne Britton <[hidden email]> wrote:
>
> I see that RFC2181, written I think 20+ years ago, says in part
>
>
>>
>> 5.2. TTLs of RRs in an RRSet
>>
>>  Resource Records also have a time to live (TTL).  It is possible for
>>  the RRs in an RRSet to have different TTLs.  No uses for this have
>>  been found that cannot be better accomplished in other ways.  This
>>  can, however, cause partial replies (not marked "truncated") from a
>>  caching server, where the TTLs for some but not all the RRs in the
>>  RRSet have expired.
>>
>>  Consequently the use of differing TTLs in an RRSet is hereby
>>  deprecated, the TTLs of all RRs in an RRSet must be the same.
> [...]
>
>
>
> but in the last few years, perhaps even a decade, TXT record usage has expanded to be used for many different and unique purposes, such as domain ownership verification and SPF data.
>
>
> What is the proper avenue to request an enhancement so each TXT record can have its own unique TTL value?
>
> Can bind be changed to do this, or must the RFC be changed first?
>
>
> Or, please give advice on how to do this today  :-)
>
>
> a live example for a client
>
>
> dig TXT newriver.edu
>
> ;; ANSWER SECTION:
> newriver.edu.           3590    IN      TXT     "docusign=b8923ecb-9c2e-4ead-ac43-17c3d522fd49"
> newriver.edu.           3590    IN      TXT     "MS=ms76391508"
>
>
> I desire to have the MS= record have a TTL of say 3600, but want the docusign record to have a TTL of 86400
>
> ... I put 3590 in there to make it easier to find it when looking at the zone file ...
>
>
>
> Verne
> --------------------------------------------------------------------
> Verne Britton, Lead Systems Programmer   voice:   (304) 293-5192 x230
> Systems Support Group                    (in WV, call 1-800-253-1558)
> West Virginia Network for                FAX:     (304) 293-5540
>     Educational Telecomputing           [hidden email]
> 837 Chestnut Ridge Road                  http://www.wvnet.edu
> Morgantown, WV  26505
> _______________________________________________
> Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list
>
> ISC funds the development of this software with paid support subscriptions. Contact us at https://www.isc.org/contact/ for more information.
>
>
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Re: different TTLs for multiple TXT records

Matus UHLAR - fantomas
In reply to this post by Verne Britton-2
On 26.09.20 09:58, Verne Britton wrote:

>I see that RFC2181, written I think 20+ years ago, says in part
>
>
>>
>>5.2. TTLs of RRs in an RRSet
>>
>>  Resource Records also have a time to live (TTL).  It is possible for
>>  the RRs in an RRSet to have different TTLs.  No uses for this have
>>  been found that cannot be better accomplished in other ways.  This
>>  can, however, cause partial replies (not marked "truncated") from a
>>  caching server, where the TTLs for some but not all the RRs in the
>>  RRSet have expired.
>>
>>  Consequently the use of differing TTLs in an RRSet is hereby
>>  deprecated, the TTLs of all RRs in an RRSet must be the same.
>[...]

>but in the last few years, perhaps even a decade, TXT record usage has
> expanded to be used for many different and unique purposes, such as domain
> ownership verification and SPF data.

unfortunately, TXT is overloaded with multiple uses. SPF record was
deprecated ...

>What is the proper avenue to request an enhancement so each TXT record can have its own unique TTL value?

not possible. IF you ask for a TXT, you must get all TXTs, the same for A, NS, MX
and all other records of the same type.

if you don't get something, it means it's not there. This is not just
documented standard - doing it differently would make DNS unreliable.

--
Matus UHLAR - fantomas, [hidden email] ; http://www.fantomas.sk/
Warning: I wish NOT to receive e-mail advertising to this address.
Varovanie: na tuto adresu chcem NEDOSTAVAT akukolvek reklamnu postu.
Windows found: (R)emove, (E)rase, (D)elete
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Re: different TTLs for multiple TXT records

Verne Britton-2
Thank you to Mark Andrews and Matus Uhlar for your quick responses ...

I see now how my thought process is fundamentally flawed  :-)

Sorry for the silly question !!



Verne
--------------------------------------------------------------------
Verne Britton, Lead Systems Programmer   voice:   (304) 293-5192 x230
Systems Support Group                    (in WV, call 1-800-253-1558)
West Virginia Network for                FAX:     (304) 293-5540
      Educational Telecomputing           [hidden email]
837 Chestnut Ridge Road                  http://www.wvnet.edu
Morgantown, WV  26505


           

On 9/26/2020 1:56 PM, Matus UHLAR - fantomas via lists.isc.org wrote:

> On 26.09.20 09:58, Verne Britton wrote:
>> I see that RFC2181, written I think 20+ years ago, says in part
>>
>>
>>>
>>> 5.2. TTLs of RRs in an RRSet
>>>
>>>  Resource Records also have a time to live (TTL).  It is possible for
>>>  the RRs in an RRSet to have different TTLs.  No uses for this have
>>>  been found that cannot be better accomplished in other ways.  This
>>>  can, however, cause partial replies (not marked "truncated") from a
>>>  caching server, where the TTLs for some but not all the RRs in the
>>>  RRSet have expired.
>>>
>>>  Consequently the use of differing TTLs in an RRSet is hereby
>>>  deprecated, the TTLs of all RRs in an RRSet must be the same.
>> [...]
>
>> but in the last few years, perhaps even a decade, TXT record usage has
>> expanded to be used for many different and unique purposes, such as domain
>> ownership verification and SPF data.
>
> unfortunately, TXT is overloaded with multiple uses. SPF record was
> deprecated ...
>> What is the proper avenue to request an enhancement so each TXT record can have its own unique TTL value?
>
> not possible. IF you ask for a TXT, you must get all TXTs, the same for A, NS, MX
> and all other records of the same type.
>
> if you don't get something, it means it's not there. This is not just
> documented standard - doing it differently would make DNS unreliable.
>
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