Re: [Idr] YANG requirements for IDR drafts (was Re: draft-head-idr-bgp-ls-isis-fr-01 - WG adoption call (6/6 to 6/20))

["Acee Lindem (acee)" <[e-mail]>]

Hi Robert,

Like the SNMP MIBs before them, the YANG models trail the routing protocol functional drafts. We have enough trouble satisfying all the references without requiring YANG models. If you pay attention during the WG document status at IETF 114, you’ll get a picture of where the base and enhancement models are in the IETF life cycle.

See one inline.

From: Idr <[e-mail]> on behalf of Robert Raszuk <[e-mail]>
Date: Tuesday, July 5, 2022 at 4:37 PM
To: Jeff Haas <[e-mail]>
Cc: Susan Hares <[e-mail]>, IDR List <[e-mail]>, lsr <[e-mail]>
Subject: Re: [Idr] YANG requirements for IDR drafts (was Re: draft-head-idr-bgp-ls-isis-fr-01 - WG adoption call (6/6 to 6/20))

Hi Jeff,

Many thx for your note. As I clarified to Sue my question was really about LSR WG not IDR :)

And the trigger was Gunter's claim that his employer's OS is already sending content of LSDB over YANG.

So I was a bit puzzled what happens with new extensions if they like ISIS reflection if they do not contain the YANG model from day one ? How is that data being encoded if at all ?

I guess you aren’t working with many vendor products. Most vendors use primarily native YANG models for configuration and operational state.

Thanks,
Acee

That answer is also important to alternative to BGP-LS discussion but let's have a separate discussion on this in the coming weeks.

Best,
R.


On Tue, Jul 5, 2022 at 10:28 PM Jeffrey Haas <[e-mail]<mailto:[e-mail]>> wrote:
Robert,


On Jun 30, 2022, at 6:56 PM, Robert Raszuk <[e-mail]<mailto:[e-mail]>> wrote:

Isn't the YANG section a requirement for all protocol extension documents before they are sent for publications these days ?


We're not yet to the point where extensions to YANG modules are part of base IETF work, but we're probably going to need to have that discussions soon across IETF.

This year will see base YANG modules for a number of protocols done.  I had hoped I could contribute toward the BGP YANG module getting done closer to start of year than not, the BGP module is more likely to be complete this fall.[1]

Once we have the base modules out, augmentations for them covering various extensions will make sense.  Prior to the publication of the base modules, we wouldn't have had the documents advance due to MISREF dependencies.

Once our base module is out, we'll have need of a number of small augmentation modules to fill in the missing features.  If you're looking to help with that work, there's probably room to start writing some drafts now.  I think the BGP YANG module is structurally solid for most configuration and operational state.  Policy is the remaining large piece of work.

That said, I think we'll find trying to write YANG for BGP-LS challenging.

The reason I am asking this is in fact in light of the other discussions we have on IDR list where at least one mode of link state state advertisement can be done using YANG encoding. Is YANG section optional in LSR WG documents which define new protocol extensions and new functionality ? If an implementation uses YANG to push LSDB how the new TLVs defined in the draft are going to be shared across ?

I think your broader question about what a streaming protocol for IGP state looks like is probably best addressed in those threads.  But, as above, it's going to be an interesting modeling exercise.

-- Jeff