What this overlay actually buys you on the security side, beyond writing firewall policies, plus an honest list of what it does not buy you, and an FAQ on VXLAN and EVPN versus plain VLANs.
Measuring the throughput cost of VXLAN on a small FortiGate with no VXLAN offload, by A/B testing the same VM over an overlay segment versus a plain VLAN, and tracing the ceiling back to the silicon.
Part 1’s static peer lists don’t scale. EVPN makes the fabric learn its own endpoints — here’s the working BGP control plane.
Standing up a single stretched Layer 2 segment between a FortiGate and a Proxmox host using unicast VXLAN, and proving the data plane before adding any complexity.