Core and data center applications are the strengths of Arista products. The distribution layer is also a good fit. For the access layer, it would be more of a niche product.
Cisco FabricPath seems to be well suited for larger datacenters where you need the scalability and flexibility that's provided. We've been able to provide our customers with much more bandwidth than they previously had throughout our datacenter and with applications generating much more east/west traffic now rather than large volumes of north/south traffic FabricPath and the nexus switches have given us the ability to provide our customers with the bandwidth that's needed to serve today's applications.
It's been fairly easy for people to learn and work with.
It has simplified network administration by utilizing Fabric Extenders which are all configured from the same switch and treated as an extension of the switch rather than as a separate entity.
I have used the Catalyst 6500 series in the past. From my point of view, the Arista surpasses the Catalyst on just about every front. Originally we were planning on implementing the Nexus 7000/7700 series switches for our core. Though a little more feature rich, it did not provide features we needed that the Arista did. The Nexus also was a confusing and complex platform to work with. Also, the Nexus was a significantly more expensive solution. Although very happy with the Arista switches we may evaluate the Aruba HPE 8400 chassis-based switches along with Arista switches in the future.
In comparison to Cisco ACI, Cisco Catalyst, and Juniper EX Switches the Nexus switches have stood their ground and we've been fairly happy with them. I like that similar to Cisco's ACI and the Juniper EX switches that I've worked with I can manage multiple chassis from one place. ACI can do this on a much larger scale though. I think Juniper limited the number of devices in a single virtual chassis to 10 or less depending on the device type. ACI can do a few hundred leafs plus their fabric extenders so if you're looking for one place to manage all your devices it can scale well beyond either the Cisco FP or Juniper EX series switches, but it also has a much steeper learning curve and completely different interface. The loop prevention built into FP has been a great improvement vs our old Catalyst switches.
FabricPath is easy enough to learn that the adoption on the team has been fairly quick. This allows us to quickly troubleshoot and allows us to meet and beat SLAs that demand we maintain 99.99%+ uptime for our paying customers.
