On Wed, Apr 20, 2022 at 06:19:09PM -0700, Andy Bierman wrote: > > If the argument is that a zone index is always allowed (even if the > usage is limited) then why does the ip-address-no-zone typedef exist > at all? There are no YANG guidelines for picking between them. >
A simple rule of thumb is that the no-zone type is adequate if the zone in which an address is valid is available from the context. - Example: If a data model configures a link-local address on an interface, then the interface provides the context and hence the zone can be omitted. - Example: If a data model refers to an IP endpoint and there is no further context information (e.g., you configure the IP address of a DNS server), then the data model should allow for a zone index to be present. I believe this is _architecturally_ the right thing to do. The other dimension is how we deal with implementations that choose to not support zoned addresses where they architecturally make sense. One option is to let such implementations declare deviations. Another is to let such implementations reject zoned addresses for leafs where zoned addresses are rightfully supported by the data model but not by the implementation. What we should not encourage is to have implementations that accept zones addresses but then silent strip away the zone since this leads to unpredictable behaviour. /js -- Jürgen Schönwälder 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/> _______________________________________________ netmod mailing list [email protected] https://www.ietf.org/mailman/listinfo/netmod
