BGP EVPN creates one VXLAN tunnel in each DC and one VXLAN tunnel between the two DCs to implement data center interconnect (DCI). As shown in Figure 8-7, BGP EVPN is used to create VXLAN tunnels in distributed gateway mode within both DC A and DC B so that the VMs deployed in each DC can communicate with each other. Leaf2 and Leaf3 are the edge devices within the DCs that connect to the backbone network. BGP EVPN is used to configure VXLAN tunnels on Leaf2 and Leaf3 so that the VXLAN packets received by one DC can be decapsulated, re-encapsulated, and sent to the peer DC. This process provides end-to-end bearing for inter-DC VXLAN packets and ensures that VMs in different DCs can communicate with each other.

Figure 8-7 Using BGP EVPN to implement DCI