The VXLAN-to-SPB deployment is where the VXLAN Gateway communicates between a VXLAN segment and an SPB domain. This type of deployment provides a solution for customers using VXLAN in their data-centers to interoperate with Fabric Connect as shown in the following figure.
The VXLAN Gateway maps the VXLAN VNID to I-SID in the following way:
When packets traverse a VXLAN segment into an SPB domain, the VXLAN VTEP decapsulates the VXLAN packet, encapsulates it with MAC-in-MAC encapsulation, and then forwards it into the SPB domain.
In the reverse direction, the VXLAN VTEP decapsulates the MAC-in-MAC packet from an SPB domain, encapsulates it with a VXLAN header, and then forwards it into a VXLAN segment.