Hi, YANG does not have 'levels'. This seems to be an ISIS specific question you should ask on the ISIS list.
/js On Sun, Jun 09, 2019 at 10:35:11AM -0400, Xufeng Liu wrote: > In Section 2.3. and many other locations, the current IS-IS model applies > the parameter overriding rule as below: > > [Quote]: > > 2.3 > <https://tools.ietf.org/html/draft-ietf-isis-yang-isis-cfg-35#section-2..3>. > Per-Level Parameters > > > Some parameters allow a per level configuration. In this case, the > parameter is modeled as a container with three configuration > locations: > > o a top-level container: corresponds to level-1-2, so the > configuration applies to both levels. > > o a level-1 container: corresponds to level-1 specific parameters. > > o a level-2 container: corresponds to level-2 specific parameters. > > +--rw priority > | +--rw value? uint8 > | +--rw level-1 > | | +--rw value? uint8 > | +--rw level-2 > | +--rw value? uint8 > > Example: > > <priority> > <value>250</value> > <level-1> > <value>100</value> > </level-1> > <level-2> > <value>200</value> > </level-2> > </priority> > > An implementation SHOULD prefer a level specific parameter over a > level-all parameter. As example, if the priority is 100 for the > level-1, 200 for the level-2 and 250 for the top-level configuration, > the implementation should use 100 for the level-1 and 200 for the > level-2. > > [End of Quote] > > > In the model, all three value leaves above have a default statement > “default 64”, which brings up my question for the following example: > > > <priority> > <value>250</value> > <level-1> > <value>100</value> > </level-1> > </priority> > > > The user does not provide a configured value for level-2. According to > Section 7.6.1. of RFC7950, because the default value is in use, “the server > MUST operationally behave as if the leaf was present in the data tree with > the default value as its value”. This means the priority value for level-2 > will be 64 (the default value), so the value 250 can never take effect as > intended in the above quoted Section 2.3. > > > Is my understanding correct? > > > Since this is a generic question, I am CC’ing NETMOD WG too. > > > Thanks, > > - Xufeng > _______________________________________________ > netmod mailing list > net...@ietf.org > https://www.ietf.org/mailman/listinfo/netmod -- Juergen Schoenwaelder Jacobs University Bremen gGmbH Phone: +49 421 200 3587 Campus Ring 1 | 28759 Bremen | Germany Fax: +49 421 200 3103 <https://www.jacobs-university.de/> _______________________________________________ Lsr mailing list Lsr@ietf.org https://www.ietf.org/mailman/listinfo/lsr
