We have seen that the Cisco SD-WAN solution is broken up into four separate planes (data, control, management, and orchestration) that play different roles and have different responsibilities in the architecture.

In this section, we will start exploring the unique functions of each network plane by deep-diving into the data plane. First, we will explore how the Cisco SD-WAN solution builds and maintains the overlay fabric. Along the way, we will introduce multiple new concepts such as TLOCs, TLOC Colors, and Tunnel Groups. Later in the chapter, we will see how the SD-WAN fabric interacts with the different types of network address translation (NAT) in the underlay. We will also explore the process of securing the data plane with IPsec and the process of key exchange.

In the configuration portion, we will look at the following lab examples that will emphasize our understanding of the data plane:

  • Lab#1: Connecting to the WAN using TLOC Extension
  • Lab#2: Controlling the topology with Restricted TLOC Colors
  • Lab#3: Controlling the topology with Tunnel Groups
  • Lab#4: Connecting to the WAN using a Loopback TLOC

At the end of the chapter, we will reiterate the essential concepts that we have seen and emphasize the key points that everybody should takeaway.