Re: [netmod] [Lsr] I-D Action: draft-ietf-lsr-ospfv3-extended-lsa-yang-10.txt

[Andy Bierman <[e-mail]>]

On Thu, Apr 14, 2022 at 1:13 PM Jürgen Schönwälder <
[e-mail]> wrote:

> On Thu, Apr 14, 2022 at 12:48:18PM -0700, Andy Bierman wrote:
>
> > The proposal is for a 2 year phase to change modules
> > that really do want a zone index.  It is not blindly removing the zone
> > index.
>
> People not reading type definitions will also not read a warning
> signs. This is blindly removing the zone index in two years, I hardly
> see a difference from doing the same (damage) today.
>
>
A 2 year advance notice is way more than normal in the open source world.

There does not seem to be any consensus on the general issues or the
specific typedef,
or even agreement that OpenConfig (and RFC 4001) got it right and IETF got
it wrong.

One set of data models treats a zone index as the normal case, not the
exception,
and the other treats a zone index as the exception.

Spinning all the YANG modules that use these typedefs is not going to
happen,
and not even clear that would help with multi-SDO integration, given the
disconnect
on the design of the typedefs.


Andy




> Lets start with one of the oldest modules affected, RFC 7317. The
> ietf-system module is using ip-address correctly (allowing DNS servers
> to be reachable via link-local addresses). So who is going to revise
> RFC 7317 in the two years? It would be strange to file an errata
> addressing a problem that will break the module in two years from
> now. In fact, there is no problem in RFC 7317, the problem is that we
> break the YANG module update rules that protect YANG modules from
> getting broken by updates to other YANG modules.
>
> And we do all of this because the name ip-address in hindsight is
> confusing?
>
> As you pointed out, an implementer can choose to ignore the optional
> zone index. However, if we remove the optional zone index, then
> implementors have no choice anymore since the data model by design
> prevents a meaningful implementation that works with link-local
> addresses. The key is that we have to trust data model writers to pick
> the right type. The assumption that every author who used ip-address
> really wanted ip-address-no-zone is very wild idea.
>
> /js (feeling lost in the modern software world)
>
> --
> Jürgen Schönwälder              Jacobs University Bremen gGmbH
> Phone: [phone]         Campus Ring 1 | 28759 Bremen | Germany
> Fax:   [phone]         <https://www.jacobs-university.de/>
>