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

Robert Raszuk <robert@raszuk.net> Mon, 07 November 2016 12:18 UTC

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From: Robert Raszuk <robert@raszuk.net>
Date: Mon, 7 Nov 2016 13:18:44 +0100
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To: Gert Doering <gert@space.net>
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Cc: heasley <heas@shrubbery.net>, idr wg <idr@ietf.org>
Subject: Re: [Idr] Vendor Defaults (was Re: Review of draft-ietf-large-community-06.txt)
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Gert,

My example was very clear and I provided example of AS_PATH prepend.

The point which you are missing is that if you execute community you should
clean up and delete it. Blind default on or off is not the way to stop
propagation of selected communities.

And if someone is inserting 5539:* it seems obvious that the intention is
that such community should get to 5539.

Best,
R.

On Nov 7, 2016 1:12 PM, "Gert Doering" <gert@space.net> wrote:

> 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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