The Connectivity Transformation Blog

It’s no secret that we at WAN Dynamics are big fans of Arista switches. There is a definite feeling when using them that the Arista Extensible Operating System (EOS) was written by engineers for engineers in order to make the network operator’s life easier. In this post, we will discuss three features that are great on their own, however when coupled together, you get an amazing amount of flexibility to solve real world problems. The sum of these features is greater than each of their parts.

WAN Dynamics received a message from a customer late one evening that no network services company wants to get: “We performed a code upgrade and broke connectivity to our disaster recovery site”. This customer had a datacenter interconnect (DCI) with BGP routing and VXLAN between the datacenters but after the EOS upgrade there was reachability issues between them. I jumped in to assist and at first glance, things looked good. The switch interfaces and BGP sessions were up and there was full connectivity from VTEP to VTEP in the datacenter interconnect. That said, MAC addresses were not being learned across VXLAN. Hmmm, wonder why that would be? I decided to check the switch logs for any potential clues as to what could be happening. Aha! in the log buffer there are messages about VXLAN being disabled: