<at the end <tp>>

From: netmod <[email protected]> on behalf of Acee Lindem (acee) 
Sent: 08 December 2022 10:55

From: netmod <[email protected]> on behalf of Andy Bierman 
<[email protected]>
Date: Wednesday, December 7, 2022 at 10:48 PM

On Wed, Dec 7, 2022 at 7:02 PM Kent Watsen <[email protected]> wrote:

>> Deprecating ip-address (and ipv4-address and ipv6-address?) is probably the
>> most disruptive
>> change to YANG that one could make.

No, the most disruptive thing would be to do what roughly 1/2 of the WG was 
proposing before, which is to introduce now a non-backwards compatible change 
in the existing definitions, which would immediately break all legacy uses.


>> A type name cannot be changed.

Nothing of the sort is being proposed here.


>> A new name can be introduced so there are 2 types that do the same thing.
>> IMO this will increase the overall confusion, and not help in any way.

We are addressing the current/existing confusion, as discussed in the last 9 
months and in a virtual interim.  Not doing anything would be truly unhelpful.

The strategy is to gradually move towards having only explicit names.   The 
first step is to introduce a new explicit name, while deprecating the legacy 
ambiguous name.  This provides time for modules to slowly migrate to the new 
name.  The second step, to be done only after the "versioning" work lands, is 
to remove the legacy deprecated name, while marking the module revision as 
having an NBC change.

IMO there is no operational problem to fix.
It is too late to change the names of the IP addresses with zones.
It is not a real problem because the server is still responsible for
accepting or sending the zone index (just like address 0.0.0.0).

For data types where the zone is never supposed to be allowed may need to
change to the no-zone variant.

Redoing all YANG modules that use the (proposed) deprecated ip-address
to some other type name is very disruptive and not needed.

I agree – this is the “cut the baby in half” option.

<tp>

The wisdom of Solomon.

With hindsight we could have done better but we are where we are and I do not 
see reports of problems arising because a module writer did not read the 
specification before assuming he knew what was meant.
The idea of making an identifier carry the semantics of an identity is not just 
one of my pet hates but an approach that leads to mistakes.  (Happily most YANG 
Doctors appreciate this so we rarely end up with XPath such as
/link/link-interface/link-interface-msd/link-interface-msd-erd etc )

On the other hand I was just looking at the IANA registries for LSR and trying 
to find which one contains a more detailed  set of TLV - the choice of 
identifiers has grown with time and does not make it easy.

Tom Petch
Acee


Andy

Between the two steps is when there may be confusion but even then, not really, 
if tooling properly warns about deprecated nodes.


Kent // contributor


_______________________________________________
netmod mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/netmod

Reply via email to