Acee Lindem <acee.i...@gmail.com> wrote: > > > On Apr 14, 2023, at 04:39, Martin Björklund <mbj+i...@4668.se> wrote: > > > > Hi, > > > > I am quite confused after reading this thread, so I had to go back to > > this first message: > > > > "Jason Sterne (Nokia)" <jason.ste...@nokia.com> wrote: > >> Hi Jeff, > >> > >> One topic that came up during the IETF 116 NETMOD meeting was > >> backwards compatibility. > >> > >>> From what I understand, a leaf (e.g. unknown-flags) that uses the > >>> unknown-bits typedef would never change its definition in YANG. It > >>> would always be defined as unknown-bits with all 64 bit definitions > >>> even as more and more bits become "known". *But* the system would > >>> suddenly stop reporting bit-0, then bit-1 in that unknown-flags leaf > >>> as those bits become known. > >> > >> Strictly speaking, that should probably be considered an NBC change > > > > Nothing has changed in the data model, so there is no way to mark the > > _data model_ as NBC. > > > > The server follows the data model, and reports which bits it doesn't > > understand. With software updates, this may change over time. This > > is simply the semantics of this state leaf. > > I agree. Removing the definition of the unknown bit in the second leaf > for unknown bits is not backward compatible but that isn’t being > proposed. > > Also, one can define a new bit in an unused position in an > augmentation - correct?
No, you cannot change the type of a leaf/leaf-list with augment. Augment can only add new nodes. /martin _______________________________________________ netmod mailing list netmod@ietf.org https://www.ietf.org/mailman/listinfo/netmod
