EOS is not operated per node, instead it is entirely software base and does basically what Nutanix and VMWare does for servers. It creates and abstracted virtual environment that allows you to manage all switches in your network. There is no one point of failure, and you can update or adjust the software straight from the virtual environment with no downtime, and minimal labor and maximum automation.
In addition Eos is interoperable with almost any third party software you want to pair if with.
Cisco operates in the opposite manner, in a proprietary manner, with software loaded per switch. Making for more difficult maintenance, more difficult upgrades, less automation, more labor, more downtime, and fewer third party interoperability options.
I do not know if this is true or not but Arista has states that Cisco could give it stuff away for free and Arista would still have lower total cost of ownership.
The larger data centers become the more necessary an EOS type structure is necessary as you simply cannot manage switches as individuals. There is a reason why Cisco has declared Arista their mortal enemy and has lost so much marketshare, systematically to Arista and white boxes, that Cisco no longer reports its largest product category (switches) as a separate product category.
Does not mean that it cannot improve itself going forward (which I am sure it is attempting to do) but yeah there is a big difference between IOS and EOS
Here is Arista’s take on EOS. EOS enables Arista to produce router functionality in the switch for a per port cost, from a slide put out last year by Arista at 33x less per port than Cisco charges for its router for the same (or even less functionality). Arista actually has a larger routing table than what Cisco or Juniper offer. That is 1/33 ($3,000 vs. $100,000).
What this all means in practicality, so far, is Arista has moved up to 15% marketshare, more or less from zero just 5 or so years ago against a monopoly and Cisco marketshare has gone down by nearly the same. Arista’s marketshare in 100GB is more than 25%. Thus the puzzlement of 25% growth rate for the rest of the year…
we can only judge the narrative from the results. And forward prognostication seems to be less aggressive than the narrative would indicate (I believe the market thinks Arista was unduly conservative in regard - and could produce another huge drop if this is not the case, like we had last quarter - although some of that has been recovered), but backward results have systematically shown the advantage.