Re: [Idr] I-D Action: draft-ietf-idr-rs-bfd-02.txt

Gert Doering <> Thu, 16 March 2017 07:38 UTC

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Date: Thu, 16 Mar 2017 08:37:53 +0100
From: Gert Doering <>
To: Robert Raszuk <>
Cc: Job Snijders <>, Gert Doering <>, idr wg <>
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Subject: Re: [Idr] I-D Action: draft-ietf-idr-rs-bfd-02.txt
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On Wed, Mar 15, 2017 at 11:38:31PM +0100, Robert Raszuk wrote:
> Thank you Job !
> So this means that every third or second customer in first two IXes
> respectively connect to exchange with at least two edge routers or it could
> be the same CE router with two interfaces :).

There's large ISPs connecting with up to 4 routers to the IXP (so, same
peer AS has multiple possible nexthops).

There's also smaller ASes buying upstream from two or more ISPs that are
all connected to the same IXP (so, same origin AS has paths through
different neighbouring ASes at the same IXP).

Optimizing the "route server shall distribute multiple paths" is only
half of the solution.  More interesting for me is "where do I need to
point my vendors to, to get them to implement proper black-hole
detection in the forwarding path, so the BGP NH can be invalidated?"
(I'm not aware of any gear that will do this right now, as in "if
IPv4 ARP or IPv6 ND fails, mark NH as invalid and look for other paths
in BGP" - but I'm always willing to learn)

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

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