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

"Reshad Rahman (rrahman)" <> Thu, 27 July 2017 19:35 UTC

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From: "Reshad Rahman (rrahman)" <>
To: "Acee Lindem (acee)" <>, Yingzhen Qu <>, Jeffrey Haas <>, "" <>
CC: "" <>, "" <>
Subject: Re: I-D Action: draft-ietf-bfd-yang-06.txt
Thread-Topic: I-D Action: draft-ietf-bfd-yang-06.txt
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Date: Thu, 27 Jul 2017 19:35:30 +0000
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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.
bfd-grouping-base-cfg-parms has only the multiplier/timers.


On 2017-07-27, 3:30 PM, "Acee Lindem (acee)" <> wrote:

>Hi Reshad, 
>On 7/27/17, 3:19 PM, "Reshad Rahman (rrahman)" <> 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
>>2 groupings is that some protocols may decide to have just the enable
>>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.
>>On 2017-07-27, 3:07 PM, "Acee Lindem (acee)" <> 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
>>>any reason why client shouldn’t use this directly.
>>>On 7/25/17, 2:33 PM, "Reshad Rahman (rrahman)" <>
>>>>Hi Yingzhen,
>>>>The grouping is available @
>>>>If you¹d like changes to the grouping, send me an email.
>>>>On 2017-07-21, 12:22 PM, "Yingzhen Qu" <> wrote:
>>>>>Hi Reshad,
>>>>>Thanks for the summary.
>>>>>Both ospf and isis models will make corresponding changes when the new
>>>>>BFD grouping is available.
>>>>>-----Original Message-----
>>>>>From: Reshad Rahman (rrahman) []
>>>>>Sent: Thursday, July 20, 2017 7:19 AM
>>>>>To: Jeffrey Haas <>rg>;
>>>>>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
>>>>>back the basic BFD config (multiplier + intervals) in IGP via a
>>>>>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).
>>>>>On 2017-07-05, 12:21 PM, "Rtg-bfd on behalf of Jeffrey Haas"
>>>>>< on behalf of> 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
>>>>>>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
>>>>>>example, the IGPs.  In particular, how do you configure the
>>>>>>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,
>>>>>>> A New Internet-Draft is available from the on-line Internet-Drafts
>>>>>>> This draft is a work item of the Bidirectional Forwarding Detection
>>>>>>>of the IETF.
>>>>>>>         Title           : YANG Data Model for Bidirectional
>>>>>>>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
>>>>>>>    and manage Bidirectional Forwarding Detection (BFD).
>>>>>>> The IETF datatracker status page for this draft is:
>>>>>>> There are also htmlized versions available at:
>>>>>>> A diff from the previous version is available at:
>>>>>>> Please note that it may take a couple of minutes from the time of
>>>>>>>submission  until the htmlized version and diff are available at
>>>>>>> Internet-Drafts are also available by anonymous FTP at: