> On 10 Sep 2015, at 12:55, Martin Bjorklund <[email protected]> wrote: > > Hi, > > I think we agreed that is ok for a YANG 1.1 module to import a YANG > 1.0 module. > > But should it also be ok for a 1.0 module to import a 1.1 module?
I think it should be illegal for a 1.0 module to import with revision if the requested revision is 1.1. > > If we make this illegal, we might run into problems. For example, > ietf-ip imports ietf-interfaces. Suppose we update ietf-interfaces > and the new version use YANG 1.1. Is it ok for a server to implement > the 1.0 version of ietf-ip and 1.1 version of ietf-interfaces? If the > answer is no, it means that we either have to update all modules to > 1.1 more or less at the same time (including vendor models!), or we > keep existing modules on 1.0 "forever". > > At the lastest interim, it was suggested that a server that implements > such a combination of models would internally promote the 1.0 module > to 1.1, and thus make this combination legal. I think we need a way for the server to identify itself to the client as 1.1-capable, and then: - 1.1-capable server: if 1.0 module X imports Y *without revision*, and the revision of Y advertised by the server (with default-revision=true), then module X is automatically interpreted as 1.1. - 1.0-only server: if 1.0 module X import Y without revision, then the latest 1.0 revision of Y is used. If 1.1 revisions exist, they are not used. > > Such a strategy should also be safe for old clients, still treating > the module as being 1.0. I am not sure about this, I think a 1.0-only client cannot work with a 1.1-capable server is some 1.1 additions are used (e.g. if-feature expressions). > > It is a bit unclear what the server should do if the 1.0 module that > it "internally promotes" to 1.1 contains something that is illegal in > 1.1, e.g.: > > default "a\xb”; We should write an erratum to 6020 making this illegal in 1.0, too. Lada > > Comments? > > > /martin > > _______________________________________________ > netmod mailing list > [email protected] > https://www.ietf.org/mailman/listinfo/netmod -- Ladislav Lhotka, CZ.NIC Labs PGP Key ID: E74E8C0C _______________________________________________ netmod mailing list [email protected] https://www.ietf.org/mailman/listinfo/netmod
