Re: [Ntp] Experimental/Private EF area: was Re: Registries document

[Miroslav Lichvar <[e-mail]>]

On Tue, Aug 01, 2023 at 01:45:36AM -0700, Harlan Stenn wrote:
> The Autokey change from Type 1 to Type 2 came out in July of 2003.
> 
> draft-ietf-ntp-autokey-00 came out in September of 2007, partway thru the
> period where ntp-4.2.4 was in use.
> 
> I heard plenty from folks who said "don't break backward compatibility".  I
> heard *nothing* about "hey, maybe we should figure out how to make the EF
> code match 5906".

Ok, so why do you want to make the change now?

> But, as I said, I'm going to be working on a document where the V1 EF is
> documented for historical purposes.

Isn't it easier to update RFC5906, when nothing has implemented it?

> The values I chose are very efficient to process in an enterprise-class or
> "carrier grade" implementation.

I don't think there is a measurable impact for an NTP server searching
EF types in a set of 8-bit values instead of 16-bit values, certainly
not in an NTP implementation like ntpd, which is mainly limited by the
OS. Can you demonstrate it? And are you sure this impact is bigger
than the impact of resolving collisions between the ntpd autokey types
and RFC5906?

> > Why would you do that? Such a waste of your project's resources.
> 
> I'm not saying we'd do it for free.

I see. If somebody else is paying for a pointless increase in
the complexity of the code, that makes it ok.

> There are apparently large organizations who, in spite of being told for a
> very long time that Autokey should not be used, still use Autokey because it
> gets them a TAI offset, and "it works just fine for them".

If they need the TAI offset, allow the Autokey LEAP extension field to
be used without the rest of Autokey and protect it by a symmetric key
or NTS. That would be a useful improvement.

> > Let's update the registries to include the ntpd Autokey EF types and
> > move on.
> 
> Please keep the V1 EF table separate from the V2 EF table.

The trouble is that there is only one table. How would an
implementation know which table is a received packet using?

-- 
Miroslav Lichvar