Figure 1 shows the use of EVPN for VXLAN overlay tunnels on the 7750 SR, 7450 ESS, or 7950 XRS when the DC provides Layer 2 connectivity and the DGW can route the traffic to the WAN through an R-VPLS and linked VPRN.
In some cases, the DGW must provide a Layer 3 default gateway function to all the hosts in a specified tenant subnet. In this case, the VXLAN data plane is terminated in an R-VPLS on the DGW, and connectivity to the WAN is accomplished through regular VPRN connectivity. The 7750 SR, 7450 ESS, and 7950 XRS support IPv4 and IPv6 interfaces as default gateways in this scenario.