In a Cisco SD-Access fabric, which node is equivalent to an access layer switch in a traditional three-tier campus network design?

The edge node in a Cisco SD-Access fabric is responsible for connecting endpoints (users, devices) to the fabric, authenticating them, applying relevant policies (e.g., micro-segmentation), and encapsulating their traffic into VXLAN tunnels. These functions directly map to the role of an access layer switch in a traditional three-tier design, which provides endpoint connectivity and initial policy enforcement.

A border node connects the SD-Access fabric to external networks, acting as a gateway, similar to a core or distribution layer switch connecting to the rest of the enterprise or the internet in a traditional design.

An intermediate node (also known as an internal border node in some contexts or a transit node) typically sits between edge and border nodes, mainly providing routing and forwarding within the fabric underlay but does not directly connect endpoints.

A control plane node (often a LISP map-server) manages the endpoint-to-location mapping database (HTDB) and provides mobility services, a function distinct from directly connecting endpoints.