Arista Routing Solutions

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21

Laszln,

Thu, Apr 28, 2016 at 12:47:45PM +0000, Laszlo Hanyecz wrote:

>
> Well,
>
> Once you eliminate the ~160k superfluous prefixes (last time I
> checked)... This is a none issue.
>
> Some work on some sort summary function would keep those devices
> alive... but we all know there is more money to be made the faster the
> device become obsolete :frowning:
>
>

Can you explain how this works? How can a router determine which prefix
is superfluous? How does it cope when a suppressed prefix is withdrawn
or a more specific prefix is added? Is this just one of those 'it works
some of the time' solutions or is this something that can be done safely
with an appropriate algorithm?

A fair chunk of the routing table is aggregable. If multiple
aggregable prefixes share the same nexthop, the HW entries can be
summarised accordingly, reducing the HW resource footprint.

Should one of the smaller prefixes be withdrawn or best path
change to another nexthop, the control plane needs to be smart
enough to adapt and reprogram the HW accordingly. It is a fairly
logical and reasonable algorithm to construct

22

Just wanted to interject, the port density of the Arista switches is quite
impressive, especially considering the price point they're at.

Not in response to any point specifically, but the major issue which stopped us buying Arista a few months ago was the rather out-dated attitude to 3rd party transceiver support.

I'm sure there are plenty of people running Arista on 3rd party optics, but all the noises that were being made by the sales and technical guys suggested that we could find ourselves abandoned by their support or a policy change in the future.

I don't fundamentally have an issue with vendor optics, except when they are excessively priced. One or two vendors will actually sell their 10Gbps optics at a price that's pretty hard to refuse, given that it's all supported. The same couldn't be said in this case.

Additionally, the insistence that we would have to buy a "small number" of Arista optics with each device for testing purposes gets old very quickly. Again, I could get on-board with this if it's just for troubleshooting, but not when these additional optics suddenly add 15% to the overall buy price of each switch. At that point, other vendors are firmly back on the table.

YMMV of course, I suspect especially if you're buying 100s of boxes.

T

23

Peter, I'd point you to https://labs.apnic.net/?p=767 for more historical
detail and a table with some (recent) predictions. The summary is that the
rate is mostly linear at around 10% per year and even 1MM routes lasts
quite comfortably beyond 5 years at the current growth rate. I am not
particularly worried about the table growth rate (or Moore's law) changing
dramatically.

With respect to the utilization of the hardware, our setup is basically the
same as Lincoln's scenario #1 and so utilization looks about the same, on
both platforms.

24

We're going to be getting some Arista gear soon and this issue came
up. They made the same noises and vague overtures of "well, you
*might* have problems with TAC if you go with 3rd party optics"...
until I said "Oh really- well, that's a deal breaker, we can't really
even consider that". And then they backpedaled at light speed and
reassured me that 3rd party optics would be fine, they just "had to
have the conversation".

Also talked to a local Arista customer, much bigger than us and using
a lot more of their gear. They have 0 Arista optics and 0 problems
with 3rd party for a few years now. IMHO the whole thing was just
sales guy FUD to try to squeeze a few extra bucks out.

25

We're going to be getting some Arista gear soon and this issue came
up. They made the same noises and vague overtures of "well, you
*might* have problems with TAC if you go with 3rd party optics"...
until I said "Oh really- well, that's a deal breaker, we can't really
even consider that". And then they backpedaled at light speed and
reassured me that 3rd party optics would be fine, they just "had to
have the conversation".

Similar experience here, but the conversation went on far too long and ultimately lost Arista the deal. There was a ridiculous amount of insistence that we would have to carry a "stock of Arista optics", but every attempt to clarify exactly what that meant (how many, what they would cost etc) failed to get a straight answer.

It's 2016 and stupid conversations about vendor optics waste time and destroy deals.

The slight difference here is that pretty much the first thing we said to Arista was that transceivers were out of the question unless they could price them reasonably** (they chose not to). On this particular deal we were probably only talking about 500 SR 10G transceivers.

We've had similar conversations with Extreme, Brocade, Solarflare and Juniper, all of whom are quite happy with us running our own parts. Solarflare even certified our parts and put them on their website (http://solarflare.com/transceivers-and-cables).

Also talked to a local Arista customer, much bigger than us and using
a lot more of their gear. They have 0 Arista optics and 0 problems
with 3rd party for a few years now. IMHO the whole thing was just
sales guy FUD to try to squeeze a few extra bucks out.

Doesn't surprise me, and I'm sure if we'd pushed for another week we could have got to this position. Unfortunately for Arista, there was another vendor quite happy to get the deal done faster and without all the BS so we voted with our feet.

Clearly, mileage will vary on this one.

T

** in this context, "reasonably" means no more than _double_ what I currently buy at.