Which two Cisco SD-Access components provide communication between traditional network elements and controller layer? (choose two)

The network data platform (NDP) is an analytics component within Cisco DNA Center used for collecting and analyzing network data, not a direct communication mechanism between traditional network elements and the controller.

The network underlay is the foundational physical or logical IP-based infrastructure (e.g., routers, switches, links) that provides IP reachability between all network devices, serving as the transport layer for the SD-Access fabric and allowing devices to communicate with the controller layer.

The fabric overlay is the virtualized network that runs on top of the underlay, utilizing technologies like VXLAN to create logical network segments and apply policies, thus enabling flexible and scalable communication across the network, managed by the controller layer.

The network control platform, specifically Cisco DNA Center, *is* the controller layer itself, responsible for managing the SD-Access fabric, rather than being a component that provides communication *to* the controller layer from traditional elements.

A partner ecosystem refers to third-party integrations and solutions that complement SD-Access, but it does not represent core communication components between traditional network elements and the controller layer.