State validation
In the last three sections of this chapter, we pushed device configs without verifying that the configuration changes had the desired effect. This is because we need all devices configured before we can validate the resulting converged operational state. Now, with all the code examples from the OpenAPI, JSON-RPC, and RESTCONF sections executed against the lab topology, we can verify whether we achieved our configuration intent—establish end-to-end reachability between loopback IP addresses of all three devices.
In this section, we’ll use the same protocols and modeling language we used earlier in this chapter to validate that each lab device can see the loopback IP address of the other two lab devices in its Forwarding Information Base (FIB) table. You can find the complete code for this section in the ch08/state directory (refer to the Further reading section) of this book’s GitHub repository. Next, we’ll examine a single example of...