In Huawei VXLAN implementations described in HCIP Datacom Campus Network documentation, the relationship between aVXLAN Network Identifier (VNI)and aBridge Domain (BD)is aone-to-one (1:1) mapping. Each BD represents a Layer 2 broadcast domain in the VXLAN overlay network, and each BD is uniquely identified by a single VNI.
The VNI is carried in the VXLAN header and is used by VTEPs to determine which virtual Layer 2 network the encapsulated traffic belongs to. When a packet is received, the VTEP decapsulates the VXLAN header and forwards the traffic to the corresponding BD based on the VNI value. Because of this mechanism, a single BD can only be associated with one VNI, and a VNI can only represent one BD.
This strict 1:1 mapping simplifies traffic forwarding, MAC address learning, and broadcast, unknown unicast, and multicast (BUM) traffic handling. It also ensures clear isolation between different virtual networks, which is essential for multi-tenant campus and data center environments. Allowing multiple BDs to map to one VNI or vice versa would break traffic isolation and complicate forwarding logic.
Therefore, Huawei VXLAN design enforces a one-to-one relationship between VNIs and BDs, making1:1the correct answer.
