Next-Generation Network Automation and Cloud Scale Routing with Arista Networks

Next-Generation Network Automation and Cloud Scale Routing with Arista Networks
Arista's portfolio is becoming quite broad

Arista Networks presented at Networking Field Day 26 (#NFD26) on September 14th, 2021 and I was privileged to have a front row seat as a delegate. What we saw was all of the interesting ways Arista is evolving their product portfolio, driving next-generation, more modernized network automation architectures then they closed with how they are building large scale routing archtectures with some very unique and novel functionality. Let's dig into the presentations.

Product Updates

Doug Gourlay started things off by walking us through some product updates from Arista since they last participated in NFD23 just about a year ago. This was a condensed review of all the products and services that have come to the market from Arista since their NFD23 presentation. Here's a quick summation:

Other updates include further development of automation/orchestration tooling and large scale routing capabilites which they did a deeper dive on in subsequent presenations. We will review those in greater detail in the next two sections.

Doug closed his portion of the presentation by making mention of some of the most prominent headwinds facing network engineers and adapting automation strategies. Basically it comes down to a lot of technical debt, doing things the way they've always been done and not taking a look at their automation strategy wholistically. All I have to say to this is "Amen." Here's hoping we as an industry start to challenge these realities and start solving them.

There are great number of challenges facing NetDevOps

If you would like to check out Doug's presentation, see it below.

Next-Generation Automation Architectures

Fred Hsu led us through some of the things that Arista has learned and leveraged using continuous integration, continuous development (CI/CD) pipelines. CI/CD pipelines are traditionally found in software development and devops environments but Fred presented applying these principals to network infrastructure automation. Though using "infrastructure as code" methodoligies is a popular topic in network engineering circles, many are in a different place in their own journey and are leveraging many different tools. Fred's slide below depicted the most common progression organizations take to network automation.

The network automation journey

Because getting starting down the path of automation can be frought with so many tools and choices about how to execute, Arista decided to solve this problem with a reference archtecture to make it easier for customers new to these mthodologies to consume. The following is what they came up with.

So this is a modular reference model that includes some best practices tools which you can swap out for others where you see fit. Fred showed off a fantastic demo of how these pieces fit together and just how powerful this model is. I won't steal his thunder, be sure to watch the video of his presentation and demos below, it's well worth the view.

Arista has put these resources into what they're calling Arista Validated Designs, which is a collections of scripts and code to help folks jumpstart their automation ambitions. Fred closed with some useful links that you can find below:

Large Scale Cloud and Enterprise Routing

The final presentation was by Alex Nichol and detailed Arista's Cloud-Grade Routing 3.0 initative for supporting very large and scalable routing infrastructures within cloud providers and enterprises that require it.

The first important point Alex made was about the realities and economics of scalable routing infrastructures. Traditionally, the cost per bit of large scale routed networks has been very costly due to custom chips spun for high throughput chassis based router systems. What Arista has determined is that merchant silicon has come a very long way and that leveraging it vs custom chips will help cut down on costs significantly. The development cycle is much more rapid to the point where merchant silicon performance is quickly outstripping custom silicon from a features, throughput and power perspective. This slide clearly illustrates that point.

Another point made is that building routing infrastructure using a disaggregated model leveraging switches that route instead of monolithic routers. This allows for greater flexibility, feature modularity for services at the edge and more of a "scale out" vs "scale up" approach that closely models L3 leaf/spine designs in the datacenter.

Scale out > Scale up

The reason the model works so well for Arista is because of the efforts they have undertaken in software to pull it all together. Making a distributed routing architecture of this scale is not trivial but due to the focus and excellence in software, it's a natural part of the progression for them. Their DNA makes evolving a truly scalable, large routed network possible.

Alex then proceeded to demo the solution and showed many paths for one to migrate their network from legacy designs to the new architecture they presented. I highly recommend checking it out below.


Arista had a lot of innovative and new things to show us at NFD26. I personally think the Arista ethos and approach to products, software development, supporting their clients and bringing greater value to the networking world is unmatched. They really are a breath of fresh air in this industry. Arista is building the tools and functionality to drive the network of the future. I highly recommend taking one of their Arista Test Drives (ATD) if you haven't seen their solutions in action. You can also pick up vEOS lab for free to play around with in your own lab environment. I'm definitely excited to play around with and share these new AVD tools ASAP!

More NFD26 Content From My Esteemed Delegate Peers!

Tim Bertino - Scaling Discussion w/ Arista

Girard Kavalines - NFD Day 1 Recap

Ed Horley - Arista - Open Source Network Automation and Tooling

Pete Welcher - NFD26: Arista Adds an Automation Architecture and Macro Segmentation to Its Cloud Grade Routing

The Art of Networking Podcast