The EVPN Loop That Wasn't: Arista ESI Multihoming in a Virtual Lab
I lost an afternoon to a “routing loop” that turned out not to be a loop at all. It was an EVPN all-active multihoming feature quietly not working in a virtual lab — and the packets ping-ponging between two switches were a symptom, not the disease. This post is two things: a refresher on how Arista ESI (Ethernet Segment) multihoming actually forwards traffic, and a write-up of the specific trap you can fall into when you build EVPN designs on vEOS/containerlab instead of real hardware. ...