CCNP SD-Access Architecture — 10 Questions

Question 1

A network engineer is deploying Cisco SD-Access in a large enterprise campus. The design requires that all user traffic be segmented by Virtual Network (VN) and that the fabric edge nodes perform SGT-based enforcement. The engineer notices that traffic between two endpoints in the same IP subnet but different VNs is being forwarded directly at the fabric edge without any SGT inspection. What is the most likely cause?

Accepted Answer

The endpoints are in the same IP subnet, so they must be in the same Virtual Network; SGT enforcement only applies to inter-VN traffic.. In Cisco SD-Access, Virtual Networks (VNs) provide Layer 3 segmentation. Traffic between endpoints in the same IP subnet but different VNs is inherently Layer 2 traffic and cannot be routed or inspected by SGT-based enforcement, which only applies to inter-VN (Layer 3) traffic. Since the endpoints are in the same subnet, the fabric edge node forwards the traffic at Layer 2 without SGT inspection, making option B correct.

Answer

The fabric edge nodes have not been configured with the proper SGT mappings.

Answer

The fabric edge nodes are operating in Layer 2 mode and do not support SGT enforcement.

Answer

The control plane node has not been configured with the correct IP-SGT mappings.

Question 2

An enterprise is migrating from a traditional three-tier campus network to Cisco SD-Access. The network engineer has deployed a fabric with a single fabric edge node and a single control plane node. Users in VLAN 10 report that they cannot reach the default gateway, which is a virtual IP on the fabric edge. The fabric edge is configured with a VLAN 10 SVI and the anycast gateway feature is enabled. What is the most likely cause of the problem?

Accepted Answer

The fabric edge node is not configured with the VLAN 10 SVI or the anycast gateway feature is disabled.. Option A is correct because the question states that the fabric edge is configured with a VLAN 10 SVI and anycast gateway is enabled, yet users cannot reach the default gateway. The most likely cause is a misconfiguration: either the SVI is missing or anycast gateway is disabled on the fabric edge. In Cisco SD-Access, the anycast gateway feature must be explicitly enabled under the SVI using the command 'ip virtual-reassembly in' and 'ip local-proxy-arp' along with the 'anycast-gateway' configuration; without it, the fabric edge cannot respond to ARP requests or route traffic for the virtual IP, breaking connectivity to the default gateway.

Answer

The control plane node is not reachable from the fabric edge, causing the fabric edge to drop traffic.

Answer

The endpoints are not configured with the correct IP address for the default gateway.

Answer

The fabric edge node is in Layer 2 mode and cannot route traffic.

Question 3

A network architect is designing an SD-Access fabric for a large enterprise campus. The design must support segmentation at Layer 2 and Layer 3 across the fabric, using a centralized control plane and policy enforcement. Which two protocols are essential for the SD-Access overlay to meet these requirements?

Accepted Answer

LISP and VXLAN. LISP (Locator/ID Separation Protocol) provides the centralized control plane for endpoint identity-to-location mapping and policy-based forwarding, while VXLAN (Virtual Extensible LAN) supplies the data-plane encapsulation needed for Layer 2 and Layer 3 segmentation across the underlay. Together, they enable scalable overlay segmentation with a centralized policy enforcement point in SD-Access.

Answer

MP-BGP and MPLS

Answer

OSPF and GRE

Answer

IS-IS and NVGRE

Question 4

An architect is planning a Cisco SD-Access fabric deployment. The design must support host mobility across multiple fabric edge nodes while ensuring consistent policy enforcement. Which fabric component is responsible for tracking endpoint locations and mapping them to the fabric?

Accepted Answer

Fabric control plane node. In Cisco SD-Access, the fabric control plane node (based on LISP) is responsible for maintaining the endpoint database (EID-to-RLOC mappings). When a host moves between fabric edge nodes, the control plane node updates the mapping, ensuring consistent policy enforcement by providing the correct location information to all edge nodes.

Answer

Fabric border node

Answer

Fabric edge node

Answer

Fabric wireless controller

Question 5

A company is deploying an SD-Access fabric with multiple sites connected via a WAN. The design must allow inter-site traffic to be forwarded without requiring a full mesh of VXLAN tunnels between all edge nodes. Which fabric role should be used to interconnect the sites?

Accepted Answer

Fabric border node. A Fabric Border Node is the correct role because it acts as the gateway between the SD-Access fabric and external networks, including WAN connections. It performs Network-to-Network Interconnection (NNI) by translating VXLAN-encapsulated traffic into the appropriate WAN transport (e.g., IPsec, MPLS) and handles inter-site routing without requiring a full mesh of VXLAN tunnels between all Edge Nodes. This design leverages the Border Node to aggregate traffic and forward it over the WAN, reducing tunnel overhead and simplifying the fabric architecture.

Answer

Fabric control plane node

Answer

Fabric edge node

Answer

Fabric WAN controller

Question 6

An architect is designing an SD-Access fabric for a campus network that requires segmentation of guest, employee, and IoT traffic. The design must use Cisco TrustSec for policy enforcement. Which component is responsible for assigning the Security Group Tag (SGT) to endpoints upon authentication?

Accepted Answer

Cisco ISE. Cisco ISE is the policy decision point in a TrustSec-enabled SD-Access fabric. When an endpoint authenticates via 802.1X, MAB, or web authentication, ISE evaluates the authentication result and the applicable authorization policy, then dynamically assigns a Security Group Tag (SGT) to the endpoint. This SGT is passed to the network access device (e.g., fabric edge node) via RADIUS attributes in the Access-Accept message, enabling consistent policy enforcement throughout the fabric.

Answer

Fabric edge node

Answer

Fabric control plane node

Answer

Cisco DNA Center

Question 7

A network team is designing the underlay for an SD-Access fabric. The design must use a routing protocol that supports fast convergence and is commonly recommended for the fabric underlay. Which routing protocol should be used?

Accepted Answer

IS-IS. IS-IS is the correct choice because it is a link-state routing protocol that provides fast convergence, is highly scalable, and is the most commonly recommended routing protocol for the underlay of an SD-Access fabric. Cisco SD-Access designs frequently use IS-IS to support the fabric's control plane and data plane requirements, leveraging its ability to handle large, flat network topologies with minimal overhead.

Answer

RIP

Answer

EIGRP

Answer

BGP

Question 8

An architect is designing an SD-Access fabric for a campus with multiple buildings. The design must support wireless clients seamlessly roaming across fabric edge nodes. Which technology is used in the fabric to provide mobility for wireless endpoints?

Accepted Answer

LISP. LISP (Locator/ID Separation Protocol) is the correct technology because it decouples the endpoint identifier (EID) from its routing locator (RLOC), enabling seamless roaming across fabric edge nodes. In SD-Access, LISP maintains a mapping database that tracks wireless endpoint locations, allowing traffic to be forwarded to the correct fabric edge without re-anchoring or tunneling changes as clients move between access points.

Answer

VXLAN

Answer

OTV

Answer

MPLS

Question 9

A company is deploying an SD-Access fabric with a centralized policy model. The design must ensure that all traffic between virtual networks (VNs) is inspected by a firewall. Which fabric role should be used to enforce this inter-VN policy?

Accepted Answer

Fabric border node. In a centralized policy model for SD-Access, the fabric border node is the correct role to enforce inter-VN traffic policies because it is the only node that can route traffic between different virtual networks (VNs) while applying firewall inspection. The border node connects the fabric to external networks and, when configured with a firewall, can enforce policies such as IP-based ACLs or zone-based firewalls for traffic crossing VNs. This design ensures that all inter-VN traffic is funneled through the border node for inspection, aligning with the centralized policy model where policy enforcement occurs at the network edge.

Answer

Fabric edge node

Answer

Fabric control plane node

Answer

Fabric WAN router

Question 10

An architect is designing an SD-Access fabric for a campus that requires high availability. The design must ensure that if one fabric edge node fails, endpoints can be re-homed to another edge node without manual intervention. Which feature should be implemented?

Accepted Answer

Anycast Layer 2 gateway. Anycast Layer 2 gateway is the correct feature because it allows multiple fabric edge nodes to share the same anycast IP and MAC address for a given VLAN. If one edge node fails, endpoints simply continue using the same gateway address, and their traffic is automatically forwarded to a surviving edge node via the fabric's underlay routing, requiring no manual intervention or protocol convergence.

Answer

HSRP

Answer

VRRP

Answer

GLBP