[netmod] Y60 - coexistence with YANG 1.0

[Martin Bjorklund <[e-mail]>]

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?

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.

Such a strategy should also be safe for old clients, still treating
the module as being 1.0.

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";

Comments?


/martin