Which node is part of the underlay network?
- edge node
- border node
- intermediate node
- control node
Explanation: The intermediate node is the node type that is part of the underlay network. While the campus fabric is composed of control plane, edge, border, and intermediate nodes, their functions differ between the underlay and overlay.
- Edge nodes, border nodes, and control plane nodes all have specific functional roles within the overlay network, such as endpoint registration, acting as a gateway to external networks, or maintaining the host tracking database.
- Intermediate nodes, by contrast, serve the underlay by providing IP reachability and connectivity between the other nodes in the fabric. As noted in the conversation history, they provide reachability within the fabric underlay but do not serve as external gateways or perform overlay-specific mapping functions.
The role of the underlay network is to establish physical connectivity using a routing protocol (typically IS-IS) to ensure packets can be delivered between fabric boundaries.
Related exam: Modules 23 – 26: Checkpoint Exam: Software-Defined Networking Answers (CCNP ENCOR v9)
