nerdexam
Cisco

350-401 · Question #1140

What is a consideration when designing a Cisco SD-Access underlay network?

The correct answer is D. The underlay switches provide endpoint physical connectivity for users.. A key consideration for a Cisco SD-Access underlay network is that the underlay switches are responsible for providing the physical connectivity for endpoint devices, while user traffic is then handled by the overlay.

Submitted by ahmad_uae· Mar 6, 2026Architecture

Question

What is a consideration when designing a Cisco SD-Access underlay network?

Options

  • AIt must support IPv4 and IPv6 underlay networks.
  • BEnd user subnets and endpoints are part of the underlay network.
  • CStatic routing is a requirement.
  • DThe underlay switches provide endpoint physical connectivity for users.

How the community answered

(42 responses)
  • B
    5% (2)
  • C
    2% (1)
  • D
    93% (39)

Why each option

A key consideration for a Cisco SD-Access underlay network is that the underlay switches are responsible for providing the physical connectivity for endpoint devices, while user traffic is then handled by the overlay.

AIt must support IPv4 and IPv6 underlay networks.

While SD-Access can support IPv6 in the overlay, the underlay typically supports IPv4, and IPv6 support in the underlay is not a strict requirement for basic SD-Access functionality.

BEnd user subnets and endpoints are part of the underlay network.

End-user subnets and endpoints belong to the overlay network (virtualized network), not the underlay network. The underlay provides IP connectivity between fabric devices.

CStatic routing is a requirement.

Static routing is generally not a requirement for the SD-Access underlay; dynamic routing protocols like OSPF, EIGRP, or IS-IS are typically used to provide IP reachability for fabric components.

DThe underlay switches provide endpoint physical connectivity for users.Correct

In Cisco SD-Access, the underlay network is the physical infrastructure that provides IP reachability for the fabric devices (e.g., fabric edge nodes, control plane nodes). The switches that form the underlay network, particularly the fabric edge nodes, are where end users physically connect their devices.

Concept tested: SD-Access underlay network role

Source: https://www.cisco.com/c/en/us/td/docs/solutions/CVD/Campus/cisco-sda-design-guide.html

Topics

#Cisco SD-Access#SD-Access underlay#Underlay network design

Community Discussion

No community discussion yet for this question.

Full 350-401 Practice