Re: [netmod] [Netconf] LC of NDMA NETCONF/RESTCONF drafts

[Juergen Schoenwaelder <[e-mail]>]

On Wed, Feb 07, 2018 at 03:03:49PM -0800, Andy Bierman wrote:
> >
> > > 2) The <get-data> operation returns all values in use.
> > >     The only way to suppress defaults is to use <origin-filter>
> > >     (e.g., request all origins except 'default')
> >
> > Or use with-defaults = trim.
> 
> Yes -- because the definition in RFC 6243 is worded to exclude nodes.
> 
> It should be clear in some draft how basic-mode applies to origin=default
> within <operational>.

Frankly, carrying the different basic modes over to <operational>
sounds like a mistake. Complexity for no real value.
 
> Applying sec 2 of 6243...
> 
> config=true:
> 
> If basic-mode=report-all then origin=default will never be present
> 
> If basic-mode=trim then origin=default is only possible if the value-in-use
> is the YANG default
> 
> If basic-mode=explicit then origin=default is only possible if the
> configured value was not
> explicitly set by a client.  Sec 2.3.1 is not clear if the YANG default
> value is relevant or not.
> It could be that if the configured value not explicitly set, then any
> value-in-use (not just the
> YANG default) could be tagged origin=default.
> 
> 
> config=false:
> 
> report-all: default ignored, no nodes treated as default
> trim: node removed if value=YANG default
> explicit: all config=false nodes are set by the server, so no nodes treated
> as default

Who needs all this to manage a network?
 
> This draft makes with-defaults mandatory-to-implement.
> It is a SHOULD implement now.  (I approve!).
>
> The with-defaults capability MUST be advertised by the NMDA server,
> including
> the basic-mode parameter. The also-supported parameter MAY be included.
> 
> Is it possible for report-all-tagged to apply to nodes that are learned
> (i.e., not origin=default)?

So here is an alternate proposal: The NMDA documents are silent about
with-defaults and if someone wants to use with-defaults with
datastores then an update of RFC 6243 needs to be written. This way,
implementations can choose to not do any of the with-defaults magic.

What we may consider, though, is to have a way to negate origin-filter
so that we can exclude specific origins - right now to emulate this
one has to (a) know all possible origins and then (b) list all origins
except the one not wanted.

/js

-- 
Juergen Schoenwaelder           Jacobs University Bremen gGmbH
Phone: [phone]         Campus Ring 1 | 28759 Bremen | Germany
Fax:   [phone]         <https://www.jacobs-university.de/>