Re: [DNSOP] I-D Action: draft-ietf-dnsop-serve-stale-09.txt

[Brian E Carpenter <[e-mail]>]

Hi Dave,

Thanks. I think that covers it. I still suspect that the original reason
was concern about int versus uint confusion, but the new text is fine.

Regards
   Brian Carpenter

On 25-Oct-19 08:35, Dave Lawrence wrote:
> [e-mail] writes:
>> A diff from the previous version is available at:
>> https://www.ietf.org/rfcdiff?url2=draft-ietf-dnsop-serve-stale-09
> 
> This revision addressed the one remaining outstanding issue that Brian
> Carpenter raised in the Gen-ART Last Call Review.  The following text
> was added to explain why a TTL with the high-order bit set is now
> handles as a large positive number (then capped down) rather than a
> negative number (and treated as zero).
> 
>     As for the change to treat a TTL with the high-order bit set as
>     positive and then clamping it, as opposed to [RFC2181] treating it as
>     zero, the rationale here is basically one of engineering simplicity
>     versus an inconsequential operational history.  Negative TTLs had no
>     rational intentional meaning that wouldn't have been satisfied by just
>     sending 0 instead, and similarly there was realistically no practical
>     purpose for sending TTLs of 2^25 seconds (1 year) or more.  There's
>     also no record of TTLs in the wild having the most significant bit set
>     in DNS-OARC's "Day in the Life" samples.  With no apparent reason for
>     operators to use them intentionally, that leaves either errors or
>     non-standard experiments as explanations as to why such TTLs might be
>     encountered, with neither providing an obviously compelling reason as
>     to why having the leading bit set should be treated differently from
>     having any of the next eleven bits set and then capped per Section 4.
> 
> I also removed the phrasing about 2181's handling of this issue as a
> "curious suggestion".  I recognize it could have an unintended
> negative connotation against the original authors, though when I wrote
> the sentence originally I meant it only with its neutral denotation.
> It was curious to me only because no rationale was provided as to why
> that particular choice had been made, despite the current assertion
> that it was obvious as to why.
> 
>