Subject: Why are we (poorly) putting IANA registries in RFCs with yang?

From: Paul Wouters <[email-masked]>
Date: Thu, 6 Dec 2018 08:36:57 -0500 (EST)

Hi,

I see a few drafts that are specifying a yang model that seems to pull in
all valid options from IANA registries. Obviously, these RFCs are going
to be out of date quickly. Then we either have to let people extrapolate
on the obvious, or write up silly Updates: documents.

For ipsec there was a discussion of only putting in "some" entries and
leave out obsolete entries. But it would require an IANA registry change
because it has no obsolete column because some (*cough* IPsec IANA Expert)
think that information should be in RFCs and not IANA Registries.

For DNS, we thought about quickly writing a draft to obsolete some very
ancient stuff more formally so the yang model could perhaps leave it out
and avoid implementors putting in stuff that is never going to get used
in real life.

Why are we doing this to ourselves?

Why can't yang modules just point to the proper IANA registries and
use the named values from those registries and look for any obsolete
and/or deprecated entries.

Paul

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From: Michael Richardson <[email-masked]>
Date: Thu, 06 Dec 2018 12:55:28 -0500

> and/or deprecated entries.

I think that there isn't any clear YANG syntax to do this.
I think it would be a good idea though.

--
Michael Richardson <[email-masked]>, Sandelman Software Works
 -= IPv6 IoT consulting =-

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From: Randy Presuhn <[email-masked]>
Date: Thu, 6 Dec 2018 10:54:47 -0800

Hi -

> I think it would be a good idea though.

Agree that this could be worth looking at, though it brings
nasty configuration management issues of its own.  Another closely
related issue was raised by Ladislav Lhotka on the netmod list
yesterday: the terms "deprecated" and "obsolete" do not have
the same meanings in yang as they do in IANA registries.

Randy

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From: Ladislav Lhotka <[email-masked]>
Date: Fri, 07 Dec 2018 08:08:51 +0100

> nasty configuration management issues of its own.  Another closely

Right. For one, there are at least two sensible ways of translating a
registry to YANG: apart from the more straightforward "enumeration"
type, it is also possible to use identities. The latter approach is
preferable if the registry only provides base identities, and other,
more specialized, identities are intended to be derived from (some of)
them. See, for example, RFC 7224.

> the same meanings in yang as they do in IANA registries.

This is the message that Randy mentioned:

https://www.ietf.org/mail-archive/web/netmod/current/msg21992.html

Hopefully, this issue can be solved relatively easily.

Lada

-- 
Ladislav Lhotka
Head, CZ.NIC Labs
PGP Key ID: 0xB8F92B08A9F76C67