[192851] in North American Network Operators' Group
Re: BFD on back-to-back connected BGP-speakers
daemon@ATHENA.MIT.EDU (jim deleskie)
Tue Nov 29 13:46:59 2016
X-Original-To: nanog@nanog.org
In-Reply-To: <20161129182341.GB16300@bamboo.slabnet.com>
From: jim deleskie <deleskie@gmail.com>
Date: Tue, 29 Nov 2016 14:46:54 -0400
To: Hugo Slabbert <hugo@slabnet.com>
Cc: NANOG list <nanog@nanog.org>
Errors-To: nanog-bounces@nanog.org
Hugo,
I've used this configuration in a past line when I may of had multiple L2
steps between L3 devices. The only concern we had was around load BFD put
on _some_ endpoint routers, if was handles on the RouteProcessor vs on line
cards.
-jim
On Tue, Nov 29, 2016 at 2:23 PM, Hugo Slabbert <hugo@slabnet.com> wrote:
> Good morning, nanog,
>
> Is there any/sufficient benefit in adding BFD onto BGP sessions between
> directly-connected routers? If we have intermediate L2 devices such that
> we can't reliably detect link failures BFD can help us quickly detect peers
> going away even when link remains up, but what about sessions with:
>
> - eBGP with peering to interface addresses (not loopback)
> - no multi-hop
> - direct back-to-back connections (no intermediate devices except patch
> panels)
>
> Possible failure scenarios where I could see this helping would be fat
> fingering (filters implemented on one or the other side drops traffic from
> the peer) or e.g. something catastrophic that causes the control plane to
> go away without any last gasp to the peer.
>
> Or is adding BFD into the mix in this type of setup getting into
> increasing effort/complexity (an additional protocol) for dimishing returns?
>
> --
> Hugo Slabbert | email, xmpp/jabber: hugo@slabnet.com
> pgp key: B178313E | also on Signal
>
>
