What maintains Layer 2 isolation between segments in a VXLAN environment?

The Virtual Network Identifier (VNID) is a 24-bit segment ID that uniquely identifies a specific virtual network segment within a VXLAN overlay. This ID is carried in the VXLAN header and ensures that traffic belonging to one virtual network is logically separated from traffic of other virtual networks, even when sharing the same underlay physical network. This provides Layer 2 isolation. The VTEP (VXLAN Tunnel Endpoint) encapsulates and decapsulates VXLAN packets, but the VNID within the header is what defines the isolation. The switch fabric is the underlying physical network and does not provide logical isolation itself. A host switch is a generic term and not specific to VXLAN isolation mechanisms.