How does the Cisco SD-Access control plane simplify routing compared with traditional designs?

Cisco SD-Access utilizes a control plane based on LISP (Locator/ID Separation Protocol) to separate Endpoint Identifiers (EIDs) from Routing Locators (RLOCs). EIDs represent end devices, while RLOCs represent the underlay network's physical locations (e.g., switch loopback interfaces). This separation means that underlay routers only need to know how to reach RLOCs, not every individual EID. This significantly reduces the size and complexity of routing tables on core network devices compared to traditional designs where every device's IP address might need to be routed. The other options are incorrect because: Routing adjacencies are still required for the underlay network to establish connectivity between RLOCs. Routers do not query all routes to the map server; rather, the map server provides mappings between EIDs and RLOCs on demand. Full routing tables are not shared; the goal of SD-Access is to simplify routing by abstracting EIDs from the underlay.