Re: [Lsr] Prefix Unreachable Announcement Use Cases

Jeff Tantsura <jefftant.ietf@gmail.com> Sun, 15 November 2020 19:29 UTC

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From: Jeff Tantsura <jefftant.ietf@gmail.com>
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Date: Sun, 15 Nov 2020 11:29:18 -0800
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Cc: Aijun Wang <wangaijun@tsinghua.org.cn>, lsr <lsr@ietf.org>, "Acee Lindem (acee)" <acee=40cisco.com@dmarc.ietf.org>
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To: Robert Raszuk <robert@raszuk.net>
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Subject: Re: [Lsr] Prefix Unreachable Announcement Use Cases
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As RIFT chair - I’d like to respond to Robert’ comment -  the example is rather  unfortunate, in RIFT disaggregation is conditional and well contained within its context, it doesn’t  affect overall scalability.

Regards,
Jeff

> On Nov 15, 2020, at 08:44, Robert Raszuk <robert@raszuk.net> wrote:
> 
> 
> Hi Aijun,
> 
> I would in fact only propose that the presented mechanism is narrowed down to invalidate BGP (service) routes - in fact their next hops. 
> 
> The reason being that the moment you make the solution generic, moreover the moment you want it to be used in RIB and data plane I am afraid you are running into similar (even if local) deaggregation mechanism like recently described in RIFT. That would kill all the scalability of advertising summary routes in the first place and I bet would face lots of opposition. 
> 
> Thx,
> R.
>  
>>> I would actually trim most use cases leaving just one - to signal remote service node (ex: PE) going down in the presence of summary route being advertised from remote area or pop. 
>  [WAJ] Yes, this may be the most useful use case, but the PUA mechanism can also apply to other scenarios. We want to make it one general solution.
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