Automation and Programmability

200 soru

Soru 41Soru

An enterprise network implements a Cisco Software-Defined Access (SD-Access) fabric architecture across a routed Layer 3 campus backbone running OSPF. Host A (10.1.10.15) attached to Fabric Edge 1 initiates unicast communication with Host B (10.1.10.22) attached to Fabric Edge 2 across the fabric overlay. Which statement correctly describes the operation and interaction of the underlay and overlay network components during packet transmission?

Cevabı ve açıklamayı göster

Cevap: Fabric Edge 1 queries the LISP Control Plane Node to resolve Host B's location, then encapsulates the frame in VXLAN using its own RLOC as the outer source IP and Fabric Edge 2's RLOC as the outer destination IP for underlay routing.

Cevap

Fabric Edge 1 queries the LISP Control Plane Node to resolve Host B's location, then encapsulates the frame in VXLAN using its own RLOC as the outer source IP and Fabric Edge 2's RLOC as the outer destination IP for underlay routing.
Software-Defined Access architectures separate control plane and data plane functions across underlay and overlay networks. LISP acts as the control plane to map Endpoint Identifiers (EIDs) to Routing Locators (RLOCs). VXLAN acts as the data plane encapsulation mechanism, wrapping the original inner Layer 2 frame inside an outer IP packet addressed from the source RLOC to the destination RLOC. The underlay network uses standard Layer 3 IP routing (such as OSPF) to transport the outer VXLAN packet across the physical topology.

Adım Adım Çözüm

1
Identify the role of the fabric Control Plane (LISP)
Fabric Edge 1 queries the LISP Control Plane Node (Map-Server/Map-Resolver) to map the destination Endpoint Identifier (EID, Host B IP/MAC) to its corresponding Routing Locator (RLOC, Fabric Edge 2 IP).
The fabric overlay relies on control plane mapping to locate endpoints dynamically across the fabric.
2
Identify the role of the fabric Data Plane (VXLAN)
Fabric Edge 1 encapsulates the original Ethernet frame into a VXLAN packet, adding an outer UDP header and outer IP header containing source RLOC (Fabric Edge 1) and destination RLOC (Fabric Edge 2).
VXLAN provides Layer 2 over Layer 3 encapsulation, allowing overlay subnet extensions over an IP underlay.
3
Identify the role of the Underlay Network (IP/OSPF)
Intermediate underlay switches forward the packet strictly using standard Layer 3 destination IP routing based on the outer IP header (Fabric Edge 2's RLOC).
The underlay network's sole responsibility is providing unicast/multicast IP reachability between RLOCs.

Anahtar Kavram

SDN Fabric Architecture: LISP Control Plane, VXLAN Overlay Data Plane, and IP Underlay Separation
Soru 42Soru

A network administrator is deploying unconfigured Cisco Catalyst switches at a new enterprise site using Cisco DNA Center Plug and Play (PnP) for automated onboarding. What infrastructure service must be available on the local staging VLAN so the factory-default switches can locate the Cisco DNA Center controller?

Cevabı ve açıklamayı göster

Cevap: A DHCP server configured to supply an IP address along with DHCP Option 43 or a domain name for DNS resolution of the controller hostname

Cevap

A DHCP server configured to supply an IP address along with DHCP Option 43 or a domain name for DNS resolution of the controller hostname
In Cisco DNA Center Network Plug and Play (PnP) zero-touch deployment, factory-default switches initiate contact with the controller using information provided during initial IP acquisition. The local DHCP server must provide an IP configuration and pass the controller's IPv4 address via DHCP Option 43, or supply a domain name allowing the switch to perform a DNS lookup for 'pnpserver.<domain_name>'.

Adım Adım Çözüm

1
Identify the Day-0 Plug and Play (PnP) discovery mechanisms for unconfigured Cisco switches.
Unconfigured switches boot up and automatically invoke the PnP agent on their default management interface.
The PnP agent requires an initial network identity (IP address) and controller location parameters to start the onboarding workflow.
2
Evaluate how the switch learns the Cisco DNA Center IP address or hostname dynamically.
The switch issues a DHCP request. The DHCP server responds with an IP lease and includes either DHCP Option 43 (which embeds the controller IP) or a domain name so the switch can resolve 'pnpserver.<localdomain>'.
DHCP Option 43 and DNS resolution are the standard local network mechanisms for PnP controller discovery.

Anahtar Kavram

Cisco DNA Center Plug and Play (PnP) Auto-Discovery Mechanisms
Soru 43Soru

A network architect is designing an automated configuration management solution for a large Enterprise network containing hundreds of Cisco IOS XE routers and NX-OS switches. The architecture requirements mandate minimizing device-level software overhead by avoiding persistent agent installations, using standard SSH/NETCONF protocol transport, leveraging YAML-formatted state files, and initiating configuration updates using a push-based model from a control node. Which configuration management tool satisfies all specified requirements, and which operational characteristics define its framework?

Cevabı ve açıklamayı göster

Cevap: Ansible, because it functions agentlessly over SSH or NETCONF using a push-based model to execute YAML-defined playbooks without requiring client software on managed devices.

Cevap

Ansible satisfies all requirements because it operates agentlessly over standard SSH or NETCONF transport, uses a push model initiated by the control node, and defines configuration tasks using YAML playbooks.
The correct answer accurately identifies Ansible's core architectural traits: it is agentless, uses SSH or NETCONF transport protocols, operates on a push model initiated by the administrator/control node, and uses readable YAML-formatted playbooks.

Adım Adım Çözüm

1
Analyze architecture requirement 1: Agentless operation over standard transport (SSH/NETCONF).
Ansible is inherently agentless for network devices, using native SSH or NETCONF sessions. Puppet and Chef typically rely on agent-based pull models or agent proxy daemons.
Eliminating agent installation on network switches/routers requires a tool designed for agentless management.
2
Analyze architecture requirement 2: Push-based execution vs Pull-based execution.
Ansible pushes configuration tasks from the control node to target devices upon command. Puppet and Chef nodes default to pulling configuration updates periodically from a central server.
Push models allow immediate targeted deployment from the control system without waiting for agent polling intervals.
3
Analyze architecture requirement 3: Data format / configuration structure.
Ansible uses YAML for its Playbooks. Puppet uses Puppet DSL (Manifests), and Chef uses Ruby DSL (Recipes/Cookbooks).
Matching the specified file format confirms Ansible as the correct mechanism.

Anahtar Kavram

Core architectural differences between Ansible (agentless, push, SSH/NETCONF, YAML), Puppet (agent-based/pull, TCP 8140, Puppet DSL), and Chef (agent-based/pull, TCP 443, Ruby DSL).
Tahmini Süre:1m 30s
Soru 44Soru

A automated network management script receives an HTTP status code of 415 Unsupported Media Type after issuing a POST request containing a structured JSON body to a REST-based API endpoint on a Cisco controller. Which HTTP request header was missing or misconfigured in the client's request payload headers to cause this failure?

Cevabı ve açıklamayı göster

Cevap: Content-Type

Cevap

The Content-Type header must be specified in the request to inform the server of the data format (such as application/json) being sent in the body.
The Content-Type request header indicates the media type (such as application/json or application/yang-data+json) of the entity-body sent to the recipient. When a client sends a POST, PUT, or PATCH request containing data but fails to include a supported Content-Type header, the server rejects the request with an HTTP 415 Unsupported Media Type status code.

Adım Adım Çözüm

1
Analyze the HTTP status code returned by the REST API endpoint.
The server returned HTTP status 415 (Unsupported Media Type).
HTTP 415 indicates that the server refuses to service the request because the payload is in a format not supported by the requested resource for the specified method.
2
Differentiate between client payload metadata headers and client expectation response headers.
Content-Type describes the request body format sent to the server, while Accept specifies acceptable response formats returned by the server.
Sending data without a proper Content-Type header prevents the API parser from identifying how to process the request payload.
3
Identify the missing header responsible for media type negotiation on incoming request bodies.
Setting Content-Type to application/json resolves the 415 status error.
The server requires explicit declaration of the data structure (e.g., JSON or XML) contained in the POST request body.

Anahtar Kavram

REST API HTTP Headers and Media Type Negotiation (Content-Type vs. Accept)
Soru 45Soru

A university healthcare network is replacing manual per-device CLI management across its regional campuses with an API-driven, controller-based automation framework. Which two statements describe the operational impacts of this automation framework on network management? (Select two.)

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: Using centralized declarative configuration templates reduces configuration drift across network devices caused by ad-hoc CLI changes.; Transitioning from periodic SNMP polling to streaming telemetry provides real-time data push mechanisms for faster network operational insight.

Cevap

The correct statements are that using centralized declarative configuration templates reduces configuration drift across network devices, and transitioning from periodic SNMP polling to streaming telemetry provides real-time data push mechanisms for faster operational insight.
Centralized declarative configuration management replaces prone-to-error manual CLI editing with unified template deployment, directly eliminating configuration drift. Additionally, moving to streaming telemetry enables push-based, near real-time telemetry streaming, which improves operational visibility over traditional pull-based SNMP polling.

Adım Adım Çözüm

1
Evaluate the impact of centralized template-driven management on configuration consistency.
Centralized declarative templates enforce identical configuration baselines across devices, mitigating manual CLI variations and drift.
Automation enforces intent-based configurations from a central controller or source of truth.
2
Evaluate monitoring shifts from legacy SNMP polling to automated telemetry.
Streaming telemetry pushes continuous data to collector systems, avoiding SNMP polling delays and high CPU utilization.
Push-based telemetry offers near real-time operational visibility into network performance.
3
Verify distractor assertions against network management standards.
Ansible is agentless (no agent needed on network devices), and standard Syslog severity numeric scales remain unchanged (0 is Emergency, 7 is Debug).
These distractors incorrectly assert architectural requirements or protocol behavior changes.

Anahtar Kavram

Impact of Automation on Network Management (Centralized Configuration & Streaming Telemetry)
Soru 46Soru

A network administrator needs to retrieve the operational state and configuration details of a specific router interface using a REST API without making any modifications to the device. Which HTTP verb should be used in the API request?

Cevabı ve açıklamayı göster

Cevap: GET

Cevap

The GET method is used to retrieve data from a REST API endpoint without altering device state.
In REST-based API architectures, the HTTP GET method maps directly to the Read operation of CRUD. It is a safe and idempotent request used strictly to fetch resource representations without modifying server state.

Adım Adım Çözüm

1
Determine the desired CRUD operation.
Fetching configuration details without making any changes corresponds to the Read operation.
The requirement explicitly states that data must be retrieved with zero modification to the device state.
2
Map the CRUD operation to the appropriate RESTful HTTP verb.
The Read operation maps to the GET HTTP method.
In REST architecture, GET is a safe, read-only verb designated specifically for data retrieval.

Anahtar Kavram

HTTP Verb to CRUD Mapping in REST APIs
Soru 47Soru

An organization is auditing its infrastructure operational model as it migrates from per-device management to a software-defined controller-based deployment (such as Cisco DNA Center). The network engineering team needs to clarify the architectural and management operational differences between these two models for their automation workflows. Which of the following statements correctly compare traditional networks with controller-based networking? (Select TWO.)

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: Controller-based architectures centralize network management and control plane intelligence, using Northbound APIs to expose abstraction layers to management applications, whereas traditional architectures require individual node management and distributed control planes.; Controller-based deployments leverage Southbound APIs (such as NETCONF, RESTCONF, or OpenFlow) to program network devices dynamically, replacing manual per-device CLI updates used in traditional networking.

Cevap

The correct statements are that controller-based architectures centralize management and control plane intelligence using Northbound APIs while traditional networks rely on per-device management and distributed control planes, and that controller-based deployments use Southbound APIs (such as NETCONF, RESTCONF, or OpenFlow) to dynamically program network devices.
The correct statements accurately contrast the two paradigms. Controller-based architectures centralize network intelligence and expose Northbound REST APIs for management applications while delegating downstream device orchestration to Southbound APIs like NETCONF, RESTCONF, or OpenFlow. Traditional networks require per-device management with distributed control plane execution on each router and switch.

Adım Adım Çözüm

1
Analyze control and management plane distribution in traditional vs. controller-based models.
Traditional networks execute control plane logic locally on each device and require individual CLI/SNMP configuration. Controller-based networks centralize control/management logic into a single software controller.
Separation of control and data planes is a core tenant of Software-Defined Networking (SDN).
2
Evaluate API directional roles (Northbound vs. Southbound).
Northbound APIs connect the controller to upper-tier management apps/scripts. Southbound APIs connect the controller downstream to network hardware nodes.
Northbound interfaces use REST APIs (HTTP GET/POST/PUT/DELETE) for abstraction, while Southbound interfaces use protocols like NETCONF, RESTCONF, or OpenFlow for device programming.
3
Evaluate distractors for architectural or REST verb inaccuracies.
The statement claiming traditional networks use controllers while SDN processes everything locally reverses the definitions. The statement claiming HTTP GET creates/updates configuration incorrectly maps HTTP GET to CRUD create/update operations.
HTTP GET is read-only in RESTful API architectures.

Anahtar Kavram

Centralized vs. Distributed Control Planes and Interface Roles (Northbound vs. Southbound APIs)
Tahmini Süre:2m 0s
Soru 48Soru

An enterprise branch location is deploying factory-default Cisco Catalyst switches using Cisco DNA Center Network Plug and Play (PnP). Which TWO methods allow an unconfigured switch to automatically locate the Cisco DNA Center controller IP address or hostname during the Day-0 onboarding process? (Choose two.)

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: Receiving a vendor-specific option value (Option 43) in the DHCP offer during IP address acquisition.; Performing a DNS lookup for the default server name 'pnpserver' within the local domain context.

Cevap

The two valid automated discovery methods are receiving DHCP Option 43 containing the controller IP address during DHCP negotiation, and querying local DNS for the default hostname 'pnpserver'.
During Day-0 PnP onboarding, a factory-default Cisco switch uses built-in logic to discover Cisco DNA Center. It first attempts Cisco Cloud Redirect, then checks the DHCP response for Option 43 (which specifies the Cisco DNA Center IP address). If Option 43 is missing, it falls back to resolving the DNS hostname 'pnpserver' within the local domain provided by DHCP Option 15.

Adım Adım Çözüm

1
Identify Day-0 Cisco DNA Center PnP controller discovery mechanisms.
Unconfigured Cisco switches query network services in a defined sequence: Cisco Cloud Redirect, DHCP Option 43, and DNS lookup for 'pnpserver'.
Day-0 Plug and Play relies on standard automated infrastructure signaling without manual CLI intervention.
2
Evaluate the role of DHCP Option 43.
DHCP Option 43 delivers the controller IP address directly inside the DHCP Offer message payload.
This enables zero-touch onboarding within private enterprise subnets.
3
Evaluate the role of DNS domain resolution.
The switch constructs 'pnpserver.<domain-name>' using the domain name learned via DHCP Option 15 and resolves it.
This acts as the fallback mechanism when Option 43 is absent.

Anahtar Kavram

Cisco DNA Center Network Plug and Play (PnP) Day-0 Controller Discovery
Soru 49Soru

Match each HTTP request method used in REST-based network management APIs to its primary function and corresponding CRUD operation.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Öğeler

GET
POST
PUT
PATCH

Eşleşmeler

Cevabı ve açıklamayı göster

Cevap

GET maps to Read (retrieves data), POST maps to Create (creates a new resource), PUT maps to Update/Replace (completely replaces a resource), and PATCH maps to Update/Modify (partially updates specific fields).
In RESTful architecture, standard HTTP request verbs correspond directly to basic CRUD database operations: GET reads resource state, POST creates new resources, PUT completely replaces existing resources, and PATCH performs partial modifications to existing resources.

Adım Adım Çözüm

1
Identify the CRUD mapping for retrieving information from a network REST API.
GET corresponds to the Read operation.
GET is a safe and idempotent method used solely to request data from an endpoint.
2
Identify the CRUD mapping for creating new resources.
POST corresponds to the Create operation.
POST submits a payload to an API endpoint to generate a new object or resource.
3
Distinguish between full replacement and partial update HTTP methods.
PUT replaces the resource entirely, while PATCH modifies only specified fields.
PUT requires a full payload representation of the resource, whereas PATCH accepts partial payloads.

Anahtar Kavram

HTTP Verbs and CRUD Operations in REST-Based APIs
Tahmini Süre:45s
Soru 50Soru

A retail enterprise replaces legacy SNMPv3 polling across its distributed branch routers with an automated model using RESTCONF and streaming telemetry. Which operational benefit does the enterprise achieve as a direct result of this architectural transition?

Cevabı ve açıklamayı göster

Cevap: Network devices push data subscription updates in real time, reducing polling bandwidth overhead and eliminating operational visibility gaps.

Cevap

Network devices push data subscription updates in real time, reducing polling bandwidth overhead and eliminating operational visibility gaps.
Transitioning from legacy SNMP polling to automated streaming telemetry allows network devices to push structured data subscriptions to collectors in near real-time. This eliminates the bandwidth overhead of constant polling requests and prevents visibility gaps between long polling intervals.

Adım Adım Çözüm

1
Analyze traditional SNMP polling limitations versus automated telemetry.
SNMP uses periodic pull operations that create bandwidth spikes and miss micro-burst events between polling cycles.
Understanding the operational limitations of legacy network management highlights the advantages of event-driven automation.
2
Evaluate the architectural behavior of streaming telemetry with RESTCONF/YANG models.
Streaming telemetry pushes operational state data continuously using subscribed streams when changes occur.
Push-based delivery lowers CPU and network overhead while delivering immediate visibility into network status changes.

Anahtar Kavram

Operational Shift from SNMP Polling to Streaming Telemetry in Automated Networks
Soru 51Soru

A network automation engineer attempts to create a new syslog host entry on a Cisco router using RESTCONF. The engineer sends an HTTP POST request to the parent container endpoint `/restconf/data/Cisco-IOS-XE-native:native/logging/host`. The API gateway responds with an HTTP status code of `409 Conflict` because a syslog host entry with the specified IP address already exists. Which HTTP request method and URI target combination must the engineer use to completely replace the existing syslog host entry configuration?

Cevabı ve açıklamayı göster

Cevap: Issue an HTTP PUT request targeting the specific resource URI `/restconf/data/Cisco-IOS-XE-native:native/logging/host/name=192.168.1.50` with the complete resource payload.

Cevap

Issue an HTTP PUT request targeting the specific resource URI `/restconf/data/Cisco-IOS-XE-native:native/logging/host/name=192.168.1.50` with the complete resource payload.
In REST-based APIs such as RESTCONF, HTTP POST maps to Create operations under a collection URI. When a resource already exists, POST yields a 409 Conflict error. To update or completely replace an existing targeted resource, the API client must send an HTTP PUT request directly to the URI identifying that specific resource instance.

Adım Adım Çözüm

1
Analyze the REST API operation and error response
The HTTP 409 Conflict status indicates that an HTTP POST request attempted to create a resource that already exists at the target location.
HTTP POST is mapped to the Create operation in CRUD and is submitted to a parent/collection endpoint. It fails if the item already exists and duplicate creation is prohibited.
2
Determine the appropriate HTTP verb for updating/replacing an existing resource
HTTP PUT is the correct verb for replacing an existing data node representation in REST APIs (Update/Replace in CRUD).
PUT is idempotent and is used to create or replace a resource at a specified, explicit URI.
3
Identify the proper URI target structure for RESTCONF resource modification
The request must target the specific item URI key (`.../logging/host/name=192.168.1.50`) rather than the broad parent container URI.
To modify a specific instance in a list, RESTCONF requires appending the key identifier to the URI path.

Anahtar Kavram

REST API CRUD Mapping (HTTP PUT vs POST)
Tahmini Süre:2m 0s
Soru 52Soru

An enterprise network engineering team is modernizing its operations infrastructure. Match each operational transition on the left with its corresponding primary benefit to network management on the right.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Öğeler

Transitioning from SNMP periodic polling to model-driven streaming telemetry
Transitioning from imperative CLI scripts to declarative configuration management
Transitioning from direct device login to API-driven controller orchestration
Transitioning from manual change windows to version-controlled automated pipeline testing

Eşleşmeler

Cevabı ve açıklamayı göster

Cevap

Matching operational transitions to network management benefits: (1) SNMP to streaming telemetry correlates to continuous push data replacing CPU-intensive polling; (2) Imperative CLI to declarative management correlates to defining desired state to eliminate configuration drift; (3) Direct device login to controller APIs correlates to abstracting hardware syntax via unified programmatic interfaces; (4) Manual change windows to automated pipeline testing correlates to pre-deployment syntax validation and rollback capabilities.
Each item accurately pairs a key transition in network management automation with its primary operational shift: streaming telemetry replaces SNMP polling overhead with real-time push streams; declarative configuration enforces intended state to reduce drift; controller APIs abstract per-device CLI complexity; and automated pipelines validate changes prior to production deployment.

Adım Adım Çözüm

1
Analyze the transition from SNMP polling to streaming telemetry
Identify telemetry push-based operational advantages
SNMP relies on pull-based periodic polling which strains CPU and lacks real-time precision. Streaming telemetry uses subscription-based push models for instant, efficient performance data.
2
Analyze imperative versus declarative configuration models
Identify drift mitigation as the primary benefit of declarative state management
Imperative scripts execute fixed command sequences regardless of baseline state, whereas declarative systems enforce the intended state, detecting and remediating unauthorized drift.
3
Analyze direct device CLI vs API-driven controller management
Identify abstraction of hardware-specific syntax via controller APIs
Controller-based automation abstracts individual box CLI syntaxes, presenting northbound APIs for intent-based fabric orchestration.
4
Analyze version control and automated CI/CD pipeline deployment
Identify automated pre-deployment testing and rollback enforcement
Pipeline automation subjects network changes to linting, dry-runs, and automated testing before applying changes live, facilitating rapid automated rollback if issues arise.

Anahtar Kavram

Core shifts in modern network management automation: push telemetry, declarative intent models, controller API abstraction, and CI/CD change validation pipelines.
Soru 53Soru

A network administrator has added a newly discovered Cisco Catalyst switch to the inventory of Cisco DNA Center. The switch is currently listed under the unassigned devices pool. Which task must the administrator perform in Cisco DNA Center before site-level settings, software images, and configuration templates can be pushed to the device?

Cevabı ve açıklamayı göster

Cevap: Assign the switch to a specific site building or floor in the Network Hierarchy.

Cevap

Assign the switch to a specific site building or floor in the Network Hierarchy.
In Cisco DNA Center, devices placed in the unassigned inventory pool cannot inherit network settings, configuration templates, or Software Image Management (SWIM) policies until they are assigned to a specific node (site, building, or floor) within the Network Hierarchy. Once assigned, the provisioning wizard pushes the appropriate site-specific configuration to the switch.

Adım Adım Çözüm

1
Analyze the Cisco DNA Center device provisioning workflow
Unassigned inventory devices cannot inherit policy definitions until they are placed in a site hierarchy
Cisco DNA Center organizes device policies, network settings, templates, and image management based on location context within the Network Hierarchy.
2
Determine the required controller action for deployment
Move the switch from unassigned inventory to a defined site location
Site assignment enables provisioning workflows by binding site-level network settings and templates to the switch.

Anahtar Kavram

Device Provisioning and Site Assignment in Cisco DNA Center
Tahmini Süre:1m 0s
Soru 54Soru

An enterprise network utilizes a centralized Software-Defined Networking (SDN) controller architecture. During a minor transport network outage, the Southbound API control channel between the SDN controller and a campus access layer switch is temporarily severed. Network monitoring indicates that existing active user sessions continue to forward frame traffic across the switch at wire speed without disruption, but new routing protocol neighbor adjacencies fail to establish and newly connected hosts cannot be populated into the forwarding tables. Which statement accurately explains the underlying separation of planes operating during this control channel outage?

Cevabı ve açıklamayı göster

Cevap: The data plane uses specialized hardware (ASICs and TCAM) pre-populated with Forwarding Information Base (FIB) entries to forward existing flows independently, while control plane intelligence required to process routing protocols and calculate new forwarding paths resides on the controller.

Cevap

The data plane uses specialized hardware (ASICs and TCAM) pre-populated with Forwarding Information Base (FIB) entries to forward existing flows independently, while control plane intelligence required to process routing protocols and calculate new forwarding paths resides on the controller.
The correct answer accurately reflects SDN architectural principles. In centralized network architectures, the control plane (which calculates paths and processes control messages like routing protocol neighbor adjacencies) resides on the centralized controller, whereas the data plane (responsible for actual packet forwarding, header rewrites, and filtering) resides on the local network switch hardware (ASICs/TCAM). Because existing forwarding rules were already programmed into the switch's hardware Forwarding Information Base (FIB) prior to the outage, the switch can independently forward active matching flows without consulting the controller. However, creating new routing adjacencies or learning new paths requires control plane interaction, which fails while the Southbound API channel is down.

Adım Adım Çözüm

1
Identify the primary functions of the Data Plane (Forwarding Plane).
The data plane is responsible for packet forwarding, encapsulation, frame check sequence verification, MAC address lookup, and ACL filtering using high-speed hardware components like ASICs and TCAM.
Data plane operations execute in hardware at line speed without requiring intervention from the main CPU or centralized controller for every packet.
2
Identify the primary functions of the Control Plane.
The control plane makes decisions about where traffic should be sent. It handles routing protocol updates (OSPF, BGP), building the Routing Information Base (RIB), ARP resolution, and signaling protocol state machines.
In SDN models, control plane functions are decoupled from network devices and centralized within the controller.
3
Analyze the impact of a Southbound API loss between the controller and switch.
When the connection breaks, no new control instructions or FIB updates can be pushed from the control plane (controller) down to the data plane (switch). However, existing FIB entries programmed into hardware ASICs allow previously learned flows to continue forwarding uninterrupted.
Hardware forwarding tables operate independently of active control plane communication once populated.

Anahtar Kavram

Control Plane and Data Plane Separation in Centralized/SDN Architectures
Soru 55Soru

Match each network device operation or architectural component to its corresponding plane of operation or processing path in a modern router or switch architecture.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Öğeler

Building the Routing Information Base (RIB) and calculating OSPF Shortest Path First (SPF) metrics via the central processor
Performing hardware-accelerated Forwarding Information Base (FIB) lookups and MAC header rewriting on ASIC line cards
Authenticating SSH administrative sessions and processing NETCONF/RESTCONF RPC requests to update YANG datastores
Generating ICMP Time Exceeded control messages for transit IP packets whose Time-to-Live (TTL) field decrements to zero

Eşleşmeler

Cevabı ve açıklamayı göster

Cevap

Building the RIB and calculating OSPF metrics maps to the Control Plane; performing FIB lookups and MAC header rewriting maps to the Data Plane; processing SSH and RESTCONF sessions maps to the Management Plane; and generating ICMP Time Exceeded messages for TTL-expired packets maps to the Exception Path (Punt to Control Plane).
The pairs accurately distinguish between topology computation (Control Plane), line-rate hardware forwarding (Data Plane), administrative system management (Management Plane), and hardware exception redirection (Punt Path).

Adım Adım Çözüm

1
Analyze routing protocol logic and topology computation
Mapped to Control Plane
Protocol logic like OSPF calculations and RIB maintenance requires general CPU processing to maintain global network state.
2
Analyze line-rate packet forwarding and hardware frame modification
Mapped to Data Plane
High-speed transit switching relies on compiled FIB/Adjacency tables programmed into hardware TCAM and ASICs.
3
Analyze network administrator management and API transactions
Mapped to Management Plane
Administrative connectivity and configuration state management are isolated within the Management Plane.
4
Analyze hardware forwarding exceptions such as TTL expiration
Mapped to Exception Path (Punt to Control Plane)
When ASIC forwarding hardware encounters conditions requiring ICMP generation, it punts the packet to the CPU process queue.

Anahtar Kavram

Separation of Control, Data, and Management Planes with Exception Handling
Soru 56Soru

A network administrator is developing an automation script to interact with a Cisco DNA Center REST API. The script needs to completely replace an existing network device interface configuration resource with a newly provided configuration payload. Which HTTP verb must the administrator use to perform this complete replacement operation?

Cevabı ve açıklamayı göster

Cevap: HTTP PUT

Cevap

HTTP PUT is the correct HTTP verb used to replace an existing REST API resource entirely with a new representation payload.
In REST-based network management APIs, HTTP PUT maps to the Update action in CRUD specifically for overwriting or completely replacing an existing target resource with the provided payload.

Adım Adım Çözüm

1
Identify the required CRUD operation
The operation requires replacing an existing interface configuration resource completely.
HTTP verbs map directly to specific CRUD (Create, Read, Update, Delete) functions in RESTful architectures.
2
Map full resource replacement to the corresponding HTTP verb
HTTP PUT is defined to replace the target resource entirely with the request payload.
Unlike HTTP PATCH (partial modification) or HTTP POST (creating a new resource), HTTP PUT overwrites the existing resource at the specified URL.

Anahtar Kavram

RESTful API HTTP Verb to CRUD Mapping (PUT vs POST/PATCH)
Soru 57Soru

An enterprise networking team is replacing a legacy campus deployment of fifty access switches that suffer from configuration drift and inconsistent QoS policies. The team evaluates migrating to a software-defined network (SDN) architecture managed by a centralized controller such as Cisco DNA Center. Which statement correctly contrasts how control plane state and policy management differ between these two architectures?

Cevabı ve açıklamayı göster

Cevap: The controller centralizes policy logic and abstracts device provisioning through Southbound APIs such as NETCONF to communicate with network hardware, whereas traditional switches build routing and forwarding decisions independently using distributed control plane protocols.

Cevap

The controller centralizes policy logic and abstracts device provisioning through Southbound APIs such as NETCONF to communicate with network hardware, whereas traditional switches build routing and forwarding decisions independently using distributed control plane protocols.
In controller-based SDN environments, control plane intelligence is centralized on the controller, which programs network forwarding hardware using Southbound APIs (such as NETCONF or RESTCONF). Traditional networks employ a distributed control plane where each network device independently processes control protocols and requires individual device configuration.

Adım Adım Çözüm

1
Analyze control plane operation in traditional networking
In traditional networking, the control plane is distributed across every device. Each switch and router runs its own control plane protocols (like OSPF, EIGRP, STP) locally to make independent forwarding decisions.
Understanding distributed control planes provides the baseline for structural comparison.
2
Analyze control plane operation in controller-based (SDN) networking
In controller-based architectures (SDN), control plane intelligence is decoupled from forwarding devices and centralized within an SDN controller (e.g., Cisco DNA Center).
Centralization enables network-wide policy management and automated provisioning.
3
Identify the communication interfaces (Southbound vs Northbound APIs)
The SDN controller communicates down to infrastructure devices using Southbound APIs (NETCONF, RESTCONF, OpenFlow) and exposes Northbound APIs (RESTful HTTP) to management applications and orchestration tools.
API distinction is a key operational difference between traditional CLI/SNMP management and controller-driven management.

Anahtar Kavram

Comparing Traditional Networks with Controller-Based Networking
Soru 58Soru

A network automation engineer issues an HTTP GET request to a Cisco IOS-XE RESTCONF API endpoint to retrieve BGP neighbor status details. The router returns the following JSON-encoded response:

{
"Cisco-IOS-XE-bgp:bgp-state-data": {
"bgp-neighbors": [
{
"neighbor-id": "192.168.10.1",
"remote-as": 65001,
"state": "Established",
"address-family": [
{
"af-name": "ipv4-unicast",
"prefixes": {
"accepted": 42,
"sent": 15
}
},
{
"af-name": "vpnv4-unicast",
"prefixes": {
"accepted": 120,
"sent": 88
}
}
]
},
{
"neighbor-id": "192.168.20.2",
"remote-as": 65002,
"state": "Active",
"address-family": [
{
"af-name": "ipv4-unicast",
"prefixes": {
"accepted": 0,
"sent": 0
}
}
]
}
]
}
}

Match each Python dictionary lookup / data extraction expression on the left to its corresponding value or evaluated data type on the right based on the JSON response payload.

Soldaki öğeye tıklayın, sonra eşleşen sağdaki öğeye tıklayın

Öğeler

data["Cisco-IOS-XE-bgp:bgp-state-data"]["bgp-neighbors"][0]["address-family"][1]["prefixes"]["accepted"]
data["Cisco-IOS-XE-bgp:bgp-state-data"]["bgp-neighbors"][1]["remote-as"]
type(data["Cisco-IOS-XE-bgp:bgp-state-data"]["bgp-neighbors"][0]["neighbor-id"])
data["Cisco-IOS-XE-bgp:bgp-state-data"]["bgp-neighbors"][0]["address-family"][0]["af-name"]

Eşleşmeler

Cevabı ve açıklamayı göster

Cevap

Each Python expression correctly matches its evaluated output: the nested lookup for the second address family accepted prefixes of neighbor 0 evaluates to 120; the remote-as of neighbor 1 evaluates to integer 65002; the data type of the quoted neighbor-id string evaluates to str; and the first address family name of neighbor 0 evaluates to "ipv4-unicast".
Each expression matches its exact JSON path evaluation according to zero-based array indexing rules and standard JSON data type mapping into Python data structures (objects to dictionaries, lists to arrays, quoted values to strings, unquoted numbers to integers).

Adım Adım Çözüm

1
Parse the top-level JSON structure and array indices using zero-based index rules.
Neighbor array index [0] corresponds to neighbor '192.168.10.1'. Neighbor array index [1] corresponds to neighbor '192.168.20.2'.
JSON arrays listed under brackets [] in Python parsing are zero-indexed.
2
Trace nested path queries down into key-value pairs and inner arrays.
Path 1 selects neighbor [0] ('192.168.10.1'), address-family array index [1] ('vpnv4-unicast'), and extracts key 'accepted' with value 120. Path 2 selects neighbor [1] ('192.168.20.2') and extracts key 'remote-as' with value 65002.
Proper path traversal requires following object keys ({}) and array indices ([]) sequentially.
3
Distinguish between JSON primitive types (string vs number/integer).
'neighbor-id' value "192.168.10.1" is enclosed in quotes (string), whereas 'remote-as' value 65002 is unquoted (integer).
JSON represents strings in double quotes and numbers without quotes.

Anahtar Kavram

JSON data structure traversal and type interpretation (arrays, objects, strings, integers)
Soru 59Soru

A network administrator is using Cisco DNA Center to onboard and configure a newly discovered switch. What is the correct order of steps required to complete the device provisioning workflow from start to finish?

Öğeleri doğru sıraya koymak için sürükleyin

Cevabı ve açıklamayı göster

Cevap

The correct sequence for provisioning a device in Cisco DNA Center is: 1) Select the switch from unassigned inventory, 2) Assign it to a network site, 3) Apply network settings and configuration templates, 4) Review the generated CLI preview and deployment schedule, and 5) Deploy the configuration and verify the switch status becomes Provisioned.
The Cisco DNA Center device provisioning workflow follows a strict logical sequence: first selecting the device from the unassigned inventory pool, assigning it to a site location in the network hierarchy, binding the relevant settings and CLI templates, reviewing the synthesized CLI configuration diff, and finally deploying the job to update the device status to Provisioned.

Adım Adım Çözüm

1
Locate the device in inventory
The target switch is selected under Provision > Network Devices > Inventory.
Provisioning must target an unassigned device discovered by Cisco DNA Center.
2
Assign device to site hierarchy
The device is mapped to a specific Area/Building/Floor location.
Site assignment determines which global/site-level policies and settings (DNS, Syslog, SNMP, NTP) apply to the device.
3
Configure templates and device settings
CLI configuration templates and site settings are associated with the switch.
Day-N operational settings and day-1 configuration templates must be attached prior to building the deployment payload.
4
Preview configuration and set schedule
The administrator validates the generated CLI diff and selects immediate or scheduled execution.
Previewing ensures configuration accuracy and prevents unintended network outages.
5
Execute deployment and verify state
Cisco DNA Center applies the configuration and updates inventory status to Provisioned.
Successful execution completes the provisioning cycle, allowing Assurance monitoring to track device health.

Anahtar Kavram

Cisco DNA Center Device Provisioning Workflow
Soru 60Soru

A network administrator is learning about the fundamentals of REST-based APIs used in network automation. Which two of the following correctly pair an HTTP verb with its corresponding CRUD operation?

Geçerli olan tümünü seçin

Cevabı ve açıklamayı göster

Cevap: HTTP GET is used to read or retrieve resource representation without modifying server state.; HTTP DELETE is used to remove a specified resource from the server.

Cevap

HTTP GET is used to read or retrieve resource representation without modifying server state, and HTTP DELETE is used to remove a specified resource from the server.
HTTP GET maps to the Read operation in CRUD and retrieves data without altering server state. HTTP DELETE maps to the Delete operation in CRUD and removes the targeted resource from the server.

Adım Adım Çözüm

1
Map HTTP verbs to their standard CRUD operations.
GET corresponds to Read, POST corresponds to Create, PUT/PATCH correspond to Update, and DELETE corresponds to Delete.
Understanding HTTP verb to CRUD operation mapping is essential for RESTful API interactions.
2
Evaluate the statements regarding HTTP verb operations.
Statements describing GET as Read/retrieve and DELETE as remove are accurate. Statements confusing POST with replacement or PUT with fetching are inaccurate.
GET is safe/read-only, DELETE removes resources, POST creates resources, and PUT updates/replaces resources.

Anahtar Kavram

REST API HTTP Verbs and CRUD Mapping
ÖncekiSayfa 3 / 10Sonraki