RE: I-D Action: draft-ietf-bfd-yang-06.txt

[Yingzhen Qu <[e-mail]>]

Hi Mahesh,

For the enable flag, I'd prefer to have it defined directly in ospf instead of using a grouping from BFD. I'm not sure how useful this grouping is, am I missing something?

Thanks,
Yingzhen

-----Original Message-----
From: Mahesh Jethanandani [mailto:[e-mail]] 
Sent: Sunday, July 30, 2017 9:43 PM
To: Yingzhen Qu <[e-mail]>
Cc: Acee Lindem (acee) <[e-mail]>; Reshad Rahman <[e-mail]>; Jeffrey Haas <[e-mail]>; [e-mail]; [e-mail]; [e-mail]
Subject: Re: I-D Action: draft-ietf-bfd-yang-06.txt

Yingzhen,

Overall the model looks good to me.

I notice that you decided to (re)define the enable flag in the model. Is that intentional?

You are aware that there is another grouping called client-base-cfg-parms that defines the enabled flag. I am not a particular fan of this split, but I am told that some client protocols just need the enable flag without the rest of the parameters of client-cfg-parms. If the split is confusing, we can collapse the enabled flag into client-cfg-parms.

Thanks.

> On Jul 30, 2017, at 10:14 AM, Yingzhen Qu <[e-mail]> wrote:
> 
> Hi all,
> 
> Please see attached ospf bfd module. Base ospf module also needs to be updated to remove the bfd enable leaf. ISIS model need to do the same change, ietf-isis-bfd.yang will look the same as ietf-ospf-bfd.yang.
> 
> Please let me know your commetns.
> 
> Thanks,
> Yingzhen
> 
> -----Original Message-----
> From: Mahesh Jethanandani [mailto:[e-mail]]
> Sent: Friday, July 28, 2017 2:25 PM
> To: Acee Lindem (acee) <[e-mail]>
> Cc: Reshad Rahman <[e-mail]>; Yingzhen Qu 
> <[e-mail]>; Jeffrey Haas <[e-mail]>; 
> [e-mail]; [e-mail]; 
> [e-mail]
> Subject: Re: I-D Action: draft-ietf-bfd-yang-06.txt
> 
> Would it not be better to call bfd-grouping-base-cfg-parms something like bfd-grouping-client-cfg-params or more simply client-cfg-params. We know it is a grouping and we know it is a bfd grouping. Why repeat?
> 
>> On Jul 27, 2017, at 7:34 PM, Acee Lindem (acee) <[e-mail]> wrote:
>> 
>> Hi Reshad,
>> 
>> Ok - I see now. I was looking at the wrong xxxx-base-cfg-parms groupings.
>> Fewer similar grouping and modules will be better ;^)
>> 
>> Thanks,
>> Acee
>> 
>> On 7/27/17, 9:03 PM, "Reshad Rahman (rrahman)" <[e-mail]> wrote:
>> 
>>> Hi Acee,
>>> 
>>> What I see @
>>> https://github.com/jhaas-pfrc/ietf-bfd-yang/blob/master/src/yang/iet
>>> f
>>> -bfd-
>>> t
>>> ypes.yang:
>>> 1) bfd-client-base-cfg-parms has leaf enabled only. BTW this 
>>> grouping is defined twice, this will be fixed when I get rid of 
>>> ietf-bfd-clients.yang
>>> 2) bfd-grouping-base-cfg-parms has multiplier/timers.
>>> 
>>> Let me get rid of the client module and have everything in the types 
>>> module.
>>> 
>>> I am not sure why you’re not seeing something different.
>>> 
>>> Regards,
>>> Reshad.
>>> 
>>> 
>>> 
>>> On 2017-07-27, 3:40 PM, "Acee Lindem (acee)" <[e-mail]> wrote:
>>> 
>>>> Hi Reshad,
>>>> 
>>>> On 7/27/17, 3:35 PM, "Reshad Rahman (rrahman)" <[e-mail]> wrote:
>>>> 
>>>>> Hi Acee,
>>>>> 
>>>>> 1) I’ll see if others chime in on this but I am fine with having 
>>>>> the client grouping in ietf-bfd-types.yang.
>>>>> 2) bfd-grouping-common-cfg-parms has much more than just the 
>>>>> multiplier/timers that the IGPs need. It also has BFD specific 
>>>>> stuff (demand-mode, BFD auth) which IMO has no business outside of BFD.
>>>> 
>>>> Agreed. 
>>>> 
>>>> 
>>>>> bfd-grouping-base-cfg-parms has only the multiplier/timers.
>>>> 
>>>> Perhaps, the addition of multiplier/timers to 
>>>> bfd-grouping-base-cfg-parms isn’t pushed to GitHub yet. This 
>>>> version 
>>>> https://github.com/jhaas-pfrc/ietf-bfd-yang/blob/master/src/yang/ie
>>>> t
>>>> f-bfd
>>>> -
>>>> t
>>>> ypes.yang only has the enabled leaf.
>>>> 
>>>> 
>>>> Thanks,
>>>> Acee
>>>> 
>>>> 
>>>>> 
>>>>> Regards,
>>>>> Reshad.
>>>>> 
>>>>> 
>>>>> 
>>>>> On 2017-07-27, 3:30 PM, "Acee Lindem (acee)" <[e-mail]> wrote:
>>>>> 
>>>>>> Hi Reshad,
>>>>>> 
>>>>>> On 7/27/17, 3:19 PM, "Reshad Rahman (rrahman)" 
>>>>>> <[e-mail]>
>>>>>> wrote:
>>>>>> 
>>>>>>> Hi Acee,
>>>>>>> 
>>>>>>> When we met we agreed to have a new model for clients. 
>>>>>>> Afterwards I decided to create a new types module, and still 
>>>>>>> went ahead with the clients module. I am fine with having 
>>>>>>> everything in the types module (no client module).
>>>>>> 
>>>>>> Although I don’t feel that strongly - I just don’t see that 
>>>>>> putting the client config params in wrappers provides any benefit.
>>>>>> As for detriments, it requires more one more local modules for 
>>>>>> validation and one more level of indirection to see what we are 
>>>>>> really allowing to be configured.
>>>>>> 
>>>>>>> 
>>>>>>> I am not sure I fully understand your comment/question on 
>>>>>>> bfd-client-ext-cfg-parms/bfd-grouping-common-cfg-parms. The 
>>>>>>> reason we have
>>>>>>> 2 groupings is that some protocols may decide to have just the 
>>>>>>> enable leaf and others may also want the multiplier/timer.
>>>>>> 
>>>>>> The bfd-client-ext-cfg-parms grouping should use 
>>>>>> bfd-types:bfd-grouping-common-cfg-parms rather than 
>>>>>> bfd-types:bfd-client-base-cfg-parms - no? This would be more 
>>>>>> obvious w/o the client module.
>>>>>> 
>>>>>> Thanks,
>>>>>> Acee
>>>>>> 
>>>>>> 
>>>>>>> 
>>>>>>> Regards,
>>>>>>> Reshad.
>>>>>>> 
>>>>>>> 
>>>>>>> 
>>>>>>> On 2017-07-27, 3:07 PM, "Acee Lindem (acee)" <[e-mail]> wrote:
>>>>>>> 
>>>>>>>> Hi Reshad,
>>>>>>>> Why do we need a new YANG model for clients? Why can’t they 
>>>>>>>> just use ietf-bfd-types.yang? I’d like to avoid the unnecessary 
>>>>>>>> levels of indirection. In fact, it looks wrong to me since the 
>>>>>>>> grouping bfd-client-ext-cfg-parms uses the grouping 
>>>>>>>> bfd-grouping-base-cfg-parms which only contains the enabled 
>>>>>>>> leaf. I believe you meant to use bfd-grouping-common-cfg-parms 
>>>>>>>> in the other new model. However, I don’t see any reason why 
>>>>>>>> client shouldn’t use this directly.
>>>>>>>> Thanks,
>>>>>>>> Acee
>>>>>>>> 
>>>>>>>> On 7/25/17, 2:33 PM, "Reshad Rahman (rrahman)" 
>>>>>>>> <[e-mail]>
>>>>>>>> wrote:
>>>>>>>> 
>>>>>>>>> Hi Yingzhen,
>>>>>>>>> 
>>>>>>>>> The grouping is available @
>>>>>>>>> https://github.com/jhaas-pfrc/ietf-bfd-yang/blob/master/src/ya
>>>>>>>>> n
>>>>>>>>> g/iet
>>>>>>>>> f
>>>>>>>>> -
>>>>>>>>> b
>>>>>>>>> f
>>>>>>>>> d
>>>>>>>>> -
>>>>>>>>> c
>>>>>>>>> lients.yang
>>>>>>>>> 
>>>>>>>>> If you¹d like changes to the grouping, send me an email.
>>>>>>>>> 
>>>>>>>>> Regards,
>>>>>>>>> Reshad.
>>>>>>>>> 
>>>>>>>>> On 2017-07-21, 12:22 PM, "Yingzhen Qu" 
>>>>>>>>> <[e-mail]>
>>>>>>>>> wrote:
>>>>>>>>> 
>>>>>>>>>> Hi Reshad,
>>>>>>>>>> 
>>>>>>>>>> Thanks for the summary.
>>>>>>>>>> 
>>>>>>>>>> Both ospf and isis models will make corresponding changes 
>>>>>>>>>> when the new BFD grouping is available.
>>>>>>>>>> 
>>>>>>>>>> Thanks,
>>>>>>>>>> Yingzhen
>>>>>>>>>> 
>>>>>>>>>> -----Original Message-----
>>>>>>>>>> From: Reshad Rahman (rrahman) [mailto:[e-mail]]
>>>>>>>>>> Sent: Thursday, July 20, 2017 7:19 AM
>>>>>>>>>> To: Jeffrey Haas <[e-mail]>; [e-mail]
>>>>>>>>>> Cc: [e-mail]; 
>>>>>>>>>> [e-mail]
>>>>>>>>>> Subject: Re: I-D Action: draft-ietf-bfd-yang-06.txt
>>>>>>>>>> 
>>>>>>>>>> We (BFD and OSPF YANG authors) had a discussion yesterday.
>>>>>>>>>> 
>>>>>>>>>> The agreement is that since IGP peers are auto-discovered, we 
>>>>>>>>>> want to add back the basic BFD config (multiplier + 
>>>>>>>>>> intervals) in IGP via a grouping.
>>>>>>>>>> BFD will provide that grouping in a specific YANG module. IGP 
>>>>>>>>>> BFD YANG will be in a separate module (separate from the main 
>>>>>>>>>> IGP module).
>>>>>>>>>> 
>>>>>>>>>> 
>>>>>>>>>> Regards,
>>>>>>>>>> Reshad.
>>>>>>>>>> 
>>>>>>>>>> On 2017-07-05, 12:21 PM, "Rtg-bfd on behalf of Jeffrey Haas"
>>>>>>>>>> <[e-mail] on behalf of [e-mail]> wrote:
>>>>>>>>>> 
>>>>>>>>>>> Thanks authors for the edits on the BFD yang module.  This 
>>>>>>>>>>> gets us a significant step closer to alignment with the rest 
>>>>>>>>>>> of IETF for network instancing.
>>>>>>>>>>> 
>>>>>>>>>>> I'd like to encourage the working group to provide feedback 
>>>>>>>>>>> on this issue and also the changes in the module.
>>>>>>>>>>> 
>>>>>>>>>>> As noted in another thread, we still have to figure out how 
>>>>>>>>>>> to deal with accommodating interaction of the BFD yang 
>>>>>>>>>>> module with client protocols.
>>>>>>>>>>> For
>>>>>>>>>>> example, the IGPs.  In particular, how do you configure the 
>>>>>>>>>>> properties of the BFD sessions that may be dynamically 
>>>>>>>>>>> instantiated based on control protocol activity?
>>>>>>>>>>> 
>>>>>>>>>>> -- Jeff
>>>>>>>>>>> 
>>>>>>>>>>> On Fri, Jun 30, 2017 at 12:55:59PM -0700, 
>>>>>>>>>>> [e-mail]
>>>>>>>>>>> wrote:
>>>>>>>>>>>> 
>>>>>>>>>>>> A New Internet-Draft is available from the on-line 
>>>>>>>>>>>> Internet-Drafts directories.
>>>>>>>>>>>> This draft is a work item of the Bidirectional Forwarding 
>>>>>>>>>>>> Detection of the IETF.
>>>>>>>>>>>> 
>>>>>>>>>>>>       Title           : YANG Data Model for Bidirectional
>>>>>>>>>>>> Forwarding
>>>>>>>>>>>> Detection (BFD)
>>>>>>>>>>>>       Authors         : Reshad Rahman
>>>>>>>>>>>>                         Lianshu Zheng
>>>>>>>>>>>>                         Mahesh Jethanandani
>>>>>>>>>>>>                         Santosh Pallagatti
>>>>>>>>>>>>                         Greg Mirsky
>>>>>>>>>>>> 	Filename        : draft-ietf-bfd-yang-06.txt
>>>>>>>>>>>> 	Pages           : 59
>>>>>>>>>>>> 	Date            : 2017-06-30
>>>>>>>>>>>> 
>>>>>>>>>>>> Abstract:
>>>>>>>>>>>>  This document defines a YANG data model that can be used 
>>>>>>>>>>>> to configure  and manage Bidirectional Forwarding Detection 
>>>>>>>>>>>> (BFD).
>>>>>>>>>>>> 
>>>>>>>>>>>> 
>>>>>>>>>>>> 
>>>>>>>>>>>> The IETF datatracker status page for this draft is:
>>>>>>>>>>>> https://datatracker.ietf.org/doc/draft-ietf-bfd-yang/
>>>>>>>>>>>> 
>>>>>>>>>>>> There are also htmlized versions available at:
>>>>>>>>>>>> https://tools.ietf.org/html/draft-ietf-bfd-yang-06
>>>>>>>>>>>> https://datatracker.ietf.org/doc/html/draft-ietf-bfd-yang-0
>>>>>>>>>>>> 6
>>>>>>>>>>>> 
>>>>>>>>>>>> A diff from the previous version is available at:
>>>>>>>>>>>> https://www.ietf.org/rfcdiff?url2=draft-ietf-bfd-yang-06
>>>>>>>>>>>> 
>>>>>>>>>>>> 
>>>>>>>>>>>> Please note that it may take a couple of minutes from the 
>>>>>>>>>>>> time of submission  until the htmlized version and diff are 
>>>>>>>>>>>> available at tools.ietf.org.
>>>>>>>>>>>> 
>>>>>>>>>>>> Internet-Drafts are also available by anonymous FTP at:
>>>>>>>>>>>> ftp://ftp.ietf.org/internet-drafts/
>>>>>>>>>>> 
>>>>>>>>> 
>>>>>>>> 
>>>>>>> 
>>>>>> 
>>>>> 
>>>> 
>>> 
>> 
> 
> Mahesh Jethanandani
> [e-mail]
> 
> 
> 
> <ietf-ospf-bfd.tree><ietf-ospf-bfd.yang>

Mahesh Jethanandani
[e-mail]