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Figure 1 depicts how packet exchange between two hosts occurs in asymmetric BGP EVPN routing model. In the asymmetric routing model, the two end hosts, Host1 and Host2 are in two different VLANs and different VNIs. Host1 intends to communicate with Host2, sends a packet with destination MAC address of of R1 because R1 is configured as the gateway on Host1. On R1, the gateway is configured on an interface that belongs to VNI Y. The packet from Host1 on ingress at R1 is first routed to VNI Y within R1 and then bridged to R2 over the VXLAN tunnel VNI Y. On receiving the packet, R2 will strip off the VXLAN header and forward the packet to Host2.
Figure 1. EVPN Asymmetric Routing Model
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