[189009] in North American Network Operators' Group
Re: Friday's Random Comment - About: Arista and FIB/RIB's
daemon@ATHENA.MIT.EDU (Baldur Norddahl)
Fri Apr 29 15:19:24 2016
X-Original-To: nanog@nanog.org
In-Reply-To: <572361E4.2060608@foobar.org>
Date: Fri, 29 Apr 2016 21:19:20 +0200
From: Baldur Norddahl <baldur.norddahl@gmail.com>
To: nanog@nanog.org
Errors-To: nanog-bounces@nanog.org
Den 29. apr. 2016 15.31 skrev "Nick Hilliard" <nick@foobar.org>:
>
> Laszlo Hanyecz wrote:
> > I'm curious about specific failure modes that can result from this, if
> > anyone can share examples/experience with it.
>
> The canonical pathological case is where the deaggregated prefixes are
> affected by upstream topology changes and suddenly your optimisations
> which saved you N% of forwarding lookup table capacity are wiped out to
> zero and you end up with no ability to look up next-hops.
With two uplinks that is highly unlikely to the point of being impossible.
There is no topology change upstream that can cause a situation where it is
not possible to do a high degree of aggregation of the full default free
routing table before loading it in the FIB.
Regards
Baldur
