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

On Fri, Apr 15, 2022 at 9:44 AM tom petch <ietfc@btconnect.com> wrote:

> From: netmod <netmod-bounces@ietf.org> on behalf of Andy Bierman <
> andy@yumaworks.com>
> Sent: 14 April 2022 22:25
>
> On Thu, Apr 14, 2022 at 1:41 PM Randy Presuhn <
> randy_presuhn@alumni.stanford.edu<mailto:randy_presuhn@alumni.stanford.edu>>
> wrote:
> Hi -
>
> On 2022-04-14 1:33 PM, Andy Bierman wrote:
> >
> >
> > On Thu, Apr 14, 2022 at 1:13 PM Jürgen Schönwälder
> > <j.schoenwaelder@jacobs-university.de<mailto:
> j.schoenwaelder@jacobs-university.de>
> > <mailto:j.schoenwaelder@jacobs-university.de<mailto:
> j.schoenwaelder@jacobs-university.de>>> 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.
> ...
>
> Why do you believe it is necessary to revise all the YANG modules that
> use the current typedefs?  Have any interoperability problems resulted
> from the use of the current definitions?  The argument that not changing
> the substance of the current definitions would somehow result in the
> need to modify the modules that have used the current definitions is
> a paper tiger, I think.
>
> There seems to be many modules where ip-address was used
> when the intention of the WG was to use ip-address-no-zone.
>
> <tp>
> Well, we really do not know.  We do know that in the past two years or so,
> when the meaning of ip-address has been pointed out to YANG module authors,
> most, but not all, have changed to the no-zone format, suggesting that they
> were unfamiliar with the use of zones in IPv6.  But they may have got it
> wrong,  The flavour of RFC4007 is that from now on, all IPv6 addresses will
> include a zone in their representation but since that is mostly the default
> zone and the default zone can be omitted then we do not often see zones in
> the representation.  To quote RFC4007
> ' This is accomplished by assigning, within the node,
>    a distinct "zone index" to each zone of the same scope to which that
>    node is attached, and by allowing all internal uses of an address to
>    be qualified by a zone index.
> '
> All internal uses! that is what an implementer should be doing with YANG
> or with anything else.
>
>

I can support just "part 1" of the proposal.

Total solution:

 - provide guidelines for YANG authors and developers
    - base + options approach vs. full + without-options approach
    - ip-address vs. ip-address-no-zone

I retract support for my own previous suggestion of allowing the zone index
to be ignored. (!)
There should not be any special exceptions for a few typedefs.
RFC 6241 is very clear about the server requirements for returning <ok> for
an <edit-config>
request. No further comment in ietf-inet-types is needed.

> Tom Petch
>
>

Andy

> Tom Petch
>
> The easiest solution is to do nothing, and force the server implementers
> to deal with it.
> A server is obligated to check all client input.
> Any request with a zone index can be rejected instead of accepted.
> This solution is compatible with the OpenConfig typedef (unless zone index
> actually used).
>
>
>
> Randy
>
> Andy
>
>
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