One of the main advantages I saw from the outset was that I could start with a single box and then grow if needed. Other than recabling, if not planned for accordingly, it seems like I can still do that. You would have an increased cost once you had to add a fabric box, but you've already had some amount of scale to get there. With a chassis system, you have the larger cost up front before you even know how you're going to scale. It's more difficult to plan what sized solution and no matter what you do, you'll probably pick the wrong one.
From: "Saku Ytti" <saku@ytti.fi>
To: "Tom Beecher" <beecher@beecher.cc>
Cc: "NANOG" <nanog@nanog.org>
Sent: Tuesday, December 24, 2024 9:28:06 AM
Subject: Re: Distributed Router Fabrics
On Tue, 24 Dec 2024 at 17:22, Tom Beecher <beecher@beecher.cc> wrote:
> It's possible I s/chip/ in my head with a different meaning than you intended, and I am answering a different question.
>
> I generally won't put all LAG members on the same ASIC, or even same linecard, for failure domain reasons. I also don't really care about possible challenges with BFD there, because I just use micro-BFD on members + min-links.
Quite, it depends what is important for your case. You may want to put
all in one chip for better feature parity in terms of QoS, counters
et.al., especially if you want them to fail as one, because you're
doing it purely for capacity, not for redundancy.
And indeed without uBFD, you're going to run LACP over one interface
in one chip at most, anyhow, and with uBFD each member are going to
run their own, anyhow.
So I wonder, what benefits is OP seeing here when it comes to
pizzabox? To me pizzzabox seems identical here to chassis box with
LACP spanning only single chip.
--
++ytti