Subject: Re: [yang-doctors] Last Call: <draft-ietf-rtgwg-yang-key-chain-15.txt> (Routing Key Chain YANG Data Model) to Proposed Standard

From: "Acee Lindem (acee)" <[email-masked]>
Date: Tue, 21 Mar 2017 17:47:09 +0000

+yang-doctors

Hi Tom, 

The draft validates with no errors/warnings with either 1.0 or 1.1 for the
version using the draft validator:

http://www.yangvalidator.com/draft-validator

But this raises an interesting point. Should the published version be 1.0
since the model doesn¹t make usage of any 1.1 constructs?

Thanks,
Acee 

On 3/21/17, 12:44 PM, "tom p." <[email-masked]> wrote:

>Why does this I-D make no mention of YANG 1.1, which has been around for
>a while now (albeit not superseding YANG 1.0)?
>
>Has the YANG module been validated against YANG 1.1?
>
>Tom Petch
>
>
>----- Original Message -----
>From: "The IESG" <[email-masked]>
>Sent: Friday, March 17, 2017 4:23 PM
>
>
>>
>> The IESG has received a request from the Routing Area Working Group WG
>> (rtgwg) to consider the following document:
>> - 'Routing Key Chain YANG Data Model'
>>   <draft-ietf-rtgwg-yang-key-chain-15.txt> as Proposed Standard
>>
>> The IESG plans to make a decision in the next few weeks, and solicits
>> final comments on this action. Please send substantive comments to the
>> [email-masked] mailing lists by 2017-04-07. Exceptionally, comments may
>be
>> sent to [email-masked] instead. In either case, please retain the
>> beginning of the Subject line to allow automated sorting.
>>
>> Abstract
>>
>>
>>    This document describes the key chain YANG data model.  A key chain
>>    is a list of elements each containing a key string, send lifetime,
>>    accept lifetime, and algorithm (authentication or encryption).  By
>>    properly overlapping the send and accept lifetimes of multiple key
>>    chain elements, key strings and algorithms may be gracefully
>updated.
>>    By representing them in a YANG data model, key distribution can be
>>    automated.  Key chains are commonly used for routing protocol
>>    authentication and other applications.  In some applications, the
>>    protocols do not use the key chain element key directly, but rather
>a
>>    key derivation function is used to derive a short-lived key from
>the
>>    key chain element key (e.g., the Master Keys used in the TCP
>>    Authentication Option.
>>
>>
>>
>>
>> The file can be obtained via
>> https://datatracker.ietf.org/doc/draft-ietf-rtgwg-yang-key-chain/
>>
>> IESG discussion can be tracked via
>>
>https://datatracker.ietf.org/doc/draft-ietf-rtgwg-yang-key-chain/ballot/
>>
>>
>> No IPR declarations have been submitted directly on this I-D.
>>
>

---

From: Martin Bjorklund <[email-masked]>
Date: Wed, 22 Mar 2017 14:23:01 +0100 (CET)

Hi,

[[email-masked]]

> since the model doesn¹t make usage of any 1.1 constructs?

Hmm, the module ietf-key-chain@2017-02-16 does in fact contain YANG
1.1 constructs; specifically is uses "if-feature" in "identity".

But even so, RFC 7950 clarifies a couple of unclear points in RFC
6020, so the general advise is that YANG 1.1 SHOULD be used in new
modules.

/martin

---

From: "Acee Lindem (acee)" <[email-masked]>
Date: Wed, 22 Mar 2017 14:01:40 +0000

Hi Martin, 

>1.1 constructs; specifically is uses "if-feature" in "identity".

Yes - funny thing is that I changed the yang-version to 1.0 in a local
copy and it still validated without errors or warnings.

>6020, so the general advise is that YANG 1.1 SHOULD be used in new

I think the only action required is to update the YANG reference from RFC
6020 to RFC 7950. 

Thanks,
Acee

---

From: tom p. <[email-masked]>
Date: Thu, 23 Mar 2017 17:37:25 +0000

----- Original Message -----
From: "Martin Bjorklund" <[email-masked]>
To: <[email-masked]>

Hi,

[[email-masked]]

<tp>

As YANG 1.1 says, some of the changes therein are not backwards
compatible so someone in future encountering a YANG 1.0 module cannot
know, without testing, whether or not it is valid with YANG 1.1.

The flavour I get from the NETMOD list is that while YANG 1.0 is not
superseded, yet it is expected to fade away gracefully and not take too
long about it; and the requirements from such as I2RS will make keeping
up-to-date-with YANG even more of an issue IMO.

So, my personal preference would be for a YANG module to indicate the
highest level that it will work with, more so than the lowest level, but
I can see that some will want the opposite!

Tom Petch

/martin