Re: [Netconf] [netconf] Comments on draft-ietf-netconf-nmda-netconf-05

[Rohit R Ranade <[e-mail]>]

Hi Juergen,

Some thoughts in-lined.

With Regards,
Rohit R Ranade

-----Original Message-----
From: Juergen Schoenwaelder [mailto:[e-mail]] 
Sent: 25 April 2018 16:12
To: Rohit R Ranade <[e-mail]>
Cc: [e-mail]; [e-mail]
Subject: Re: [Netconf] [netconf] Comments on draft-ietf-netconf-nmda-netconf-05

On Wed, Apr 25, 2018 at 04:22:24AM +0000, Rohit R Ranade wrote:
> Hi All,
> 
> I plan to implement this draft and hence had some implementation related clarifications.
> 
> 
> 1.       I feel that there should be more text added about "origin" filtering mechanism. I am not clear about some aspects of origin filtering.
> 
> RFC 8342 : NMDA RFC provides the below example
> 
> <interfaces xmlns:or="urn:ietf:params:xml:ns:yang:ietf-origin"
>                  or:origin="or:intended">
>        <interface>
>          <name>lo0</name>
>          <description>loopback</description>
>          <ip-address or:origin="or:system">127.0.0.1</ip-address>
>          <ip-address>::1</ip-address>
>        </interface>
>      </interfaces>
> If user provides <origin-filter> as "system" ONLY, then he will NOT get this record in output. Because the keys have originated from "intended" . Right ?
> So, If user wants to get the system originated data, he MUST give all the origins in the <origin-filter> where the keys of the system data have originated from. Can you please confirm whether this is OK.

I would expect that <origin-filter>or:system</origin-filter> would select the ip-address tagged with or:origin="or:system" and that the system would return any necessary container or list elements and the necessary key elements (since otherwise the value returned is just useless). So the result would be:

      <interfaces xmlns:or="urn:ietf:params:xml:ns:yang:ietf-origin"
                  or:origin="or:intended">
        <interface>
          <name>lo0</name>
          <ip-address or:origin="or:system">127.0.0.1</ip-address>
        </interface>
      </interfaces>

[Rohit R Ranade] While this looks OK for the origin filter, for the negated-origin-filter, for the same example given above, if <negated-origin-filter> or:intended<negated-origin-filter> is given, then it will give the "system" related nodes even if it encountered the "intended" node first, which the user definitely dint want included in the output ? Can you please confirm whether this is OK.
   Can you please clarify whether the negated filter has higher priority than the selected filter ?

> Another example given in RFC 8342 is as below:
>      <interfaces xmlns:or="urn:ietf:params:xml:ns:yang:ietf-origin"
>                  or:origin="or:intended">
>        <interface or:origin="or:system">
>          <name>lo0</name>
>          <ip-address>127.0.0.1</ip-address>
>          <ip-address>::1</ip-address>
>        </interface>
>      </interfaces>
> 
> ?  Here keys are originated from "system", but it is under container of "intended". So if user gives "system" for "origin-filter", the output will still NOT have this instance output ?

We allow origin values on containers or lists in order to inherit them, i.e., to achieve a more compact encoding. Anyway, if a leaf node matches, then I think any encompassing containers and list should be included in the result so that the matching leaf can be reported. So you would return

      <interfaces xmlns:or="urn:ietf:params:xml:ns:yang:ietf-origin"
                  or:origin="or:intended">
        <interface or:origin="or:system">
          <name>lo0</name>
          <ip-address>127.0.0.1</ip-address>
          <ip-address>::1</ip-address>
        </interface>
      </interfaces>

instead of not returning anything at all.

> ?  Also the container is not defined as "presence" in C.3.  Interface Example, but still it has origin whether that is Ok ?

Why not?
[Rohit R Ranade] RFC 8342 Section 5.3.4
" The origin applies to all configuration nodes except non-presence containers.  "



/js

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