Re: Arista 7280QR-C36 Viability

[Tyler Conrad via NANOG <nanog () lists nanog org>]

Depending on how much memory you get it with, it can do fine in that role.
I've seen people on original Jericho systems at 95% utilization on the DFZ
(without flexroute or fib compression) drop down to 45% utilization just by
enabling the fib compression knob.

The things I'd be concerned with are the default 8GB of system memory (some
were sold with 32GB), and the cross-connect architecture - it's two Jericho
ASICs plugged in back to back with some oversub between them, so if it's a
lightly loaded box it should perform well, but at full capacity it can
potentially cause traffic drops if the egress interface isn't on the same
asic; there's a knob to enable a local-bias here. I'm also not aware of any
avenues to get software downloads or support for grey-market equipment.

As far as the licensing piece that was mentioned, there are no licensing
keys for routing on Arista. Generally the only time you'll see hard license
enforcement is for crypto compliance.

On Mon, Dec 1, 2025 at 1:56 PM Tom Beecher via NANOG <nanog () lists nanog org>
wrote:

> > At the risk of the Streisand effect, what am I missing about the Arista
> > 7280QR-C36? It looks like a great router for small ISPs (great price,
> large
> > packet buffers, good port selection, meaningful hardware routes). That
> > said, it looks to be right on the border of DFZ viability. It supports
> > "over 1M" routes, but I currently have about 1,036,824 in my route table.
> > How much over is "over"? What happens in EOS when it goes over?
>
>
> 1. That's a lot of ports that are gonna go unused in a network edge use
> case.
> 2. There is always some fudge from the vendor provided scale numbers. You
> can usually exceed them a little bit, but how much very much depends. When
> you exhaust the FIB memory, it's gonna stop working. Best case it crashes
> and reloads, worst case it wedges and needs a 1 finger salute.
>
> This box isn't designed to be an edge router. You couldn't take a full V4
> and V6 table from a single provider on it without it falling over. Could
> you possibly make it work in some environments? Sure. But just because you
> can, etc, etc
>
> On Mon, Dec 1, 2025 at 8:57 AM Mike Hammett via NANOG <
> nanog () lists nanog org>
> wrote:
>
> > At the risk of the Streisand effect, what am I missing about the Arista
> > 7280QR-C36? It looks like a great router for small ISPs (great price,
> large
> > packet buffers, good port selection, meaningful hardware routes). That
> > said, it looks to be right on the border of DFZ viability. It supports
> > "over 1M" routes, but I currently have about 1,036,824 in my route table.
> > How much over is "over"? What happens in EOS when it goes over?
> >
> > What's the "next best" box for that role?
> >
> >
> >
> > -----
> > Mike Hammett
> > Intelligent Computing Solutions
> > http://www.ics-il.com
> >
> > Midwest-IX
> > http://www.midwest-ix.com
> >
> >
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