Andy Bierman <[email protected]> writes: > On Mon, Jun 12, 2017 at 10:21 AM, Juergen Schoenwaelder < > [email protected]> wrote: > >> On Fri, Jun 09, 2017 at 10:55:20AM +0000, Bogaert, Bart (Nokia - >> BE/Antwerp) wrote: >> > >> > We have a question regarding the statistics container as defined in the >> > interfaces-state model. This container defines one mandatory leaf >> > (discontinuity-time) while all other leafs are optional. What is the >> > rationale behind this leaf being mandatory and not an optional field? >> > >> > It does not make a lot of sense to return a discontinuity-time value and >> no >> > counters if none of the counters are relevant for a specific interface. >> > >> > Another alternative could be to add, via a deviation, a when clause to >> the >> > container indicating for which ifType(s) the container is (or is not) >> > present. But that would lead to not supporting the IETF interfaces model >> to >> > the full extent. >> > >> >> The discontinuity-time is relevant for _any_ counter associated with >> an interface, regardless whether the counter is defined in the >> interfaces model or elsewhere. I have a hard time to imagine an >> interface that has zero counters. >> >> > The mandatory-stmt is very confusing for config=false nodes. Mandatory=true > means > an <rpc-reply> must contain an instance of the mandatory leaf.
I don't think it is that confusing. RFC 7950 defines what a valid data tree means and "mandatory" are among the constraints. I agree though that in terms of a management protocol it means different things for config true and false data, but this is true also for default values and maybe other YANG concepts as well. > > Mandatory=false does not mean optional-to-implement although it sure > looks that way for config=false nodes. Only if-feature can make a node > optional to implement. I don't think this interpretation is supported by any text in the YANG spec. State data nodes that are optional needn't be implemented. Lada > > > > /js > > > Andy > > -- >> Juergen Schoenwaelder Jacobs University Bremen gGmbH >> Phone: +49 421 200 3587 Campus Ring 1 | 28759 Bremen | Germany >> Fax: +49 421 200 3103 <http://www.jacobs-university.de/> >> >> _______________________________________________ >> netmod mailing list >> [email protected] >> https://www.ietf.org/mailman/listinfo/netmod >> > _______________________________________________ > netmod mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/netmod -- Ladislav Lhotka, CZ.NIC Labs PGP Key ID: 0xB8F92B08A9F76C67 _______________________________________________ netmod mailing list [email protected] https://www.ietf.org/mailman/listinfo/netmod
