Ops confuses a VXLAN VNI with the local VLAN ID while reading control-plane advertisements on a county leaf. What is the correct distinction?
Select an answer to reveal the explanation.
Short Explanation
Treat the VNI like the city’s parcel code for an overlay neighborhood, and the VLAN ID like the door tag on one building’s access switch. At the VTEP you map that local door tag into the VNI the fabric actually forwards on. They are related by mapping, not by being the same number everywhere.
Full Explanation
A VXLAN Network Identifier (VNI) uniquely identifies an overlay segment in both the VXLAN header and EVPN control-plane context. Access VLANs on a leaf are local constructs that map to VNIs at encapsulation/decapsulation time; they need not equal the VNI numerically and are not required to ride unchanged across the underlay. Confusing the two leads to wrong troubleshooting assumptions about what EVPN is advertising versus what a trunk port tags. The underlay forwards outer IP/UDP toward VTEP addresses while the VNI stays in the VXLAN header.