Re: [Idr] Vendor Defaults (was Re: Review of draft-ietf-large-community-06.txt)

Gert Doering <gert@space.net> Mon, 07 November 2016 12:13 UTC

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Date: Mon, 7 Nov 2016 13:12:51 +0100
From: Gert Doering <gert@space.net>
To: Robert Raszuk <robert@raszuk.net>
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Cc: heasley <heas@shrubbery.net>, "idr@ietf.org" <idr@ietf.org>
Subject: Re: [Idr] Vendor Defaults (was Re: Review of draft-ietf-large-community-06.txt)
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Hi,

On Mon, Nov 07, 2016 at 12:16:41AM +0100, Robert Raszuk wrote:
> > The attributes changing will induce BGP churn as updates propagate.
> > That churn may in fact trigger load-induced brown-outs and further
> > induce churn.
> 
> BGP communities are not used in best path selection 

While the communities *themselves* are not, many (most? all?) major transit
providers offer communities to influence the value local-pref is set to,
on ingress from their customers.

So, if a customer sends 5539:70 or 5539:130 to us, this will end up 
setting local-pref 70 or local-pref 130, and that *will* influence 
path selection.

So, while your statement is true, it's lacking real-world consideration.

Gert Doering
        -- NetMaster
-- 
have you enabled IPv6 on something today...?

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