How VXLAN data plane works? in other words how traffic is forwarded in VXLAN network? we have two type of traffic, When source and destination are in the same VLAN and when source and destination are in different VLAN. in this section we discuss L2 forwarding which two nodes in the same VLAN communicate with each other. In the next section we discuss inter vlan routing in VXLAN network.
As you see in the topology, we have two leaf switches in VXLAN network. we have also two server, one of them with MAC and IPX is connected to leaf1 and the other with MACY and IPY is connected to leaf2 switch. both servers are in VLAN 140 and VLAN 140 is mapped to VNI 50140 in VXLAN network.
As you know, MACs and IPs are advertised over MP-BGP EVPN route type 2. so both the Leaf1 and Leaf2 switches learn and know the MACs and IPs that are connected locally or that are learned via MP-BGP. for example, In the Leaf1 switch, MACY is learned, with L2 VNI 50140 and with Next Hop V2.
server1 sends traffic to destination server2 with source, MACX in layer 2 and IPX in layer 3 and with destination MACY in layer 2 and IPY in layer 3. When the Leaf1 switch receives the traffic, it matches a record in the MAC table that points to the next hop V2 with L2 VNI 50140. The original frame is encapsulated in a VXLAN packet with VNI 50140 and source V1, VTEP address of Leaf1 and destination V2, VTEP address of the Leaf2 switch.