Chapter 21 – EVPN and VXLAN

In the last chapter, we looked at how we can use MPLS to create a Layer 2 VPN (L2VPN) for a Virtual Private LAN Service (VPLS). In this chapter, we’ll extend those concepts and explore how Ethernet VPNs (EVPNs) and Virtual Extensible LANs (VXLANs) expand the capabilities of Layer 2 services like a bridge-switch network over a Layer 3 infrastructure consisting of IP routers. We’ll start with an overview of the service EVPNs provide, and then compare Layer 2 VPNs with EVPNs. We’ll examine the multi-protocol EVPN control plane (MPBGP) and the types of route advertisements used. Then we’ll look at underlays and overlays and how they can be confusing. We’ll end with a look at how VXLANs can form the data plane for EVPNs and why this is attractive. Finally, we’ll look at configuring some of the basics of EVPNs on our Illustrated Network.