About Translating Incoming VLANs
Sometimes a VLAN translation is required or desired. One such use case is when a service provider has multiple customers connecting to the same physical switch using the same VLAN encapsulation, but they are not and should not be on the same Layer 2 segment. In such cases translating the incoming VLAN to a unique VLAN that is then mapped to a VNI is the right way to extending the segment. In the figure below two customers, Blue and Red are both connecting to the leaf using VLAN 10 as their encapsulation.
Customers Blue and Red should not be on the same VNI. In this example VLAN 10 for Customer Blue (on interface E1/1) is mapped/translated to VLAN 100, and VLAN 10 for customer Red (on interface E1/2) is mapped to VLAN 200. In turn, VLAN 100 is mapped to VNI 10000 and VLAN 200 is mapped to VNI 20000.
On the other leaf, this mapping is applied in reverse. Incoming VXLAN encapsulated traffic on VNI 10000 is mapped to VLAN 100 which in turn is mapped to VLAN 10 on Interface E1/1. VXLAN encapsulated traffic on VNI 20000 is mapped to VLAN 200 which in turn is mapped to VLAN 10 on Interface E1/2.
You can configure VLAN translation between the ingress (incoming) VLAN and a local (translated) VLAN on a port. For the traffic arriving on the interface where VLAN translation is enabled, the incoming VLAN is mapped to a translated VLAN that is VXLAN enabled.
On the underlay, this is mapped to a VNI, the inner dot1q is deleted, and switched over to the VXLAN network. On the egress switch, the VNI is mapped to a translated VLAN. On the outgoing interface, where VLAN translation is configured, the traffic is converted to the original VLAN and egressed out. Refer to the VLAN counters on the translated VLAN for the traffic counters and not on the ingress VLAN. Port VLAN (PV) mapping is an access side feature and is supported with both multicast and ingress replication for flood and learn and MP-BGP EVPN mode for VXLAN.