VXLAN Journey - Part 02 - What is VXLAN and how it works (Cisco Nexus Switch) - Basic control plane learning
We have covered some basic theories/concepts regarding VXLAN and implemented a simple topology using data-plane learning in Part 01 . Now we will use the same topology to implement VXLAN using control-plane learning. Why I am calling the topology - control-plane learning? This time we will use routing protocols - OSPF, BGP etc. to build our VXLAN tunnels dynamically and exchange forwarding information. Let's talk about our routing protocols first. We will use OSPF for underlay unicast routing. For overlay we will use BGP-EVPN address family to exchange forwarding information. BGP EVPN Type-2 routes ( MAC/IP Advertisement Route ) will be used to forward traffic between our clients. BUM traffic will be forwarded using BGP EVPN Type-3 routes . For simplicity we will not use multicast protocol (PIM etc.) for BUM traffic. Instead we will rely on BGP Head-End-Replication (also known as ingress replication ) for BUM traffic forwarding. A little refresher about - RD and RT in BGP...