View Full Cisco CCNP Data Center 300-635 Exam Dumps and Practice Test Dumps

 

Question 141.

Which Cisco Nexus feature enables Python scripts to run directly on supported NX-OS switches?

1. Guest Shell
   2. HSRP
   3. VTP
   4. UDLD

Correct Answer: 1

Explanation:

Cisco NX-OS supports on-box programmability features that allow scripts and automation tools to run directly on supported Nexus platforms. Guest Shell provides a Linux container environment where Python and other utilities can be used for local automation, troubleshooting, data collection, and integration tasks. This can reduce dependence on an external automation server for certain workflows. HSRP provides gateway redundancy, VTP distributes VLAN information in supported environments, and UDLD detects unidirectional links. Engineers using Guest Shell should still consider resource limits, security, software compatibility, and operational governance before placing automation directly on production switches.

Question 142.

Which benefit is provided by running automation locally on a Nexus switch through an on-box environment?

1. It removes all security controls
   2. It can execute local operational tasks without depending entirely on an external automation host
   3. It automatically replaces the switch operating system
   4. It eliminates the need for testing

Correct Answer: 2

Explanation:

On-box automation can perform local monitoring, event handling, data processing, or administrative tasks without requiring every action to originate from an external orchestration server. This can reduce latency and allow workflows to continue even when external management connectivity is temporarily unavailable. However, local automation does not bypass security, replace NX-OS, or eliminate the need for testing. Scripts running on a production switch must be carefully controlled because faulty code could consume resources or make unintended changes. Good practices include source control, testing, logging, and least-privilege access.

Question 143.

Which NX-OS feature is designed to react automatically to defined system events and execute configured actions?

1. OSPF only
   2. vPC only
   3. Embedded Event Manager
   4. FabricPath only

Correct Answer: 3

Explanation:

Embedded Event Manager, or EEM, allows NX-OS devices to detect specified events and trigger actions automatically. Events can include interface state changes, syslog messages, timer events, environmental conditions, or other detectable conditions. EEM can then execute CLI commands, scripts, or other actions depending on platform support. This makes it useful for local remediation, alerting, and operational automation. OSPF, vPC, and FabricPath are networking technologies rather than general event-driven automation frameworks. EEM workflows should be tested carefully because automated actions can execute immediately when matching conditions occur.

Question 144.

Which EEM component defines the condition that causes an applet or policy to run?

1. Action
   2. Variable
   3. CLI parser only
   4. Event

Correct Answer: 4

Explanation:

The event portion of an EEM policy defines the trigger condition that causes the automation to run. The event might be a syslog pattern, interface status change, timer, threshold, or another supported detector. Actions specify what should occur after the trigger is matched. Separating events from actions allows engineers to create event-driven workflows where operational conditions automatically invoke remediation, logging, or notification. Careful event selection is important because overly broad triggers can cause automation to run unexpectedly or too frequently.

Question 145.

A Nexus switch should automatically collect troubleshooting information whenever a critical interface goes down. Which feature is most appropriate?

1. EEM policy
   2. HSRP preemption
   3. DHCP relay
   4. VLAN pruning

Correct Answer: 1

Explanation:

An EEM policy can monitor for an interface-down event or matching syslog message and automatically run commands to collect troubleshooting data. For example, it could record interface counters, neighboring devices, logs, and routing information immediately after the event occurs. This is useful because transient problems can disappear before an engineer begins manual investigation. HSRP, DHCP relay, and VLAN pruning do not provide general event-triggered automation. EEM should be designed carefully so data collection does not consume excessive resources during repeated failures.

Question 146.

Which development approach is best when the same event-handling logic must be reused across many Nexus switches?

1. Configure every switch differently
   2. Store the policy in source control and deploy it through automation
   3. Manually type the policy after each failure
   4. Remove version history

Correct Answer: 2

Explanation:

Storing EEM policies or related scripts in source control allows the organization to maintain one reviewed version and deploy it consistently to many switches. Automation can then distribute the same policy while applying device-specific variables where needed. This reduces configuration drift and makes changes easier to audit. Manually recreating policies increases the chance of syntax differences and errors. Version control also provides change history and supports rollback when a new automation revision causes problems.

Question 147.

Which Cisco Nexus interface is commonly used to execute CLI commands programmatically over HTTP or HTTPS?

1. NX-API CLI
   2. STP
   3. CDP
   4. PIM

Correct Answer: 1

Explanation:

NX-API CLI allows software to submit supported Nexus CLI commands through HTTP or HTTPS rather than an interactive terminal session. Responses can be returned in structured formats such as JSON or XML, making them easier for applications to parse. This provides a convenient transition from traditional CLI operations to programmable management. STP, CDP, and PIM are network protocols and do not provide a general HTTP-based programming interface. Secure implementations should use HTTPS, appropriate authentication, and careful command validation.

Question 148.

Why is structured NX-API output preferable to screen scraping CLI text?

1. It guarantees the device never changes software versions
   2. It removes authorization controls
   3. It provides predictable fields that applications can parse more reliably
   4. It automatically converts every operation into an idempotent task

Correct Answer: 3

Explanation:

Structured output provides named fields and predictable data structures, making scripts less dependent on spacing, headings, or other human-oriented formatting. Screen scraping can break when CLI output changes between software versions or platforms. JSON and XML are easier to validate, traverse, and transform programmatically. Structured output does not eliminate authorization or guarantee idempotency, and software upgrades can still modify API schemas. Nevertheless, machine-readable data greatly improves automation reliability compared with unstructured text parsing.

Question 149.

Which Cisco Nexus programmability method is most appropriate when a developer wants model-driven configuration using YANG rather than CLI commands?

1. NETCONF or RESTCONF
   2. CDP only
   3. HSRP only
   4. NTP only

Correct Answer: 1

Explanation:

NETCONF and RESTCONF are model-driven interfaces that work with YANG data models. They provide structured access to configuration and operational state rather than requiring the client to send CLI commands. NETCONF typically uses XML-based RPCs over SSH, while RESTCONF uses HTTP methods with JSON or XML representations. CDP, HSRP, and NTP serve other networking functions. Model-driven programmability can improve consistency because the available data and configuration structures are defined by schemas.

Question 150.

Which YANG element generally represents a single leaf-level value such as an interface description?

1. container only
   2. leaf
   3. module import only
   4. notification only

Correct Answer: 2

Explanation:

A YANG leaf represents a single value within a data model. Examples include an interface description, administrative state, MTU value, or other scalar attribute. Containers group related child nodes, while lists represent repeated collections of structured entries. YANG models use data types and constraints to define acceptable leaf values. Understanding basic YANG node types helps developers navigate NETCONF or RESTCONF payloads and identify which fields can be queried or modified.

Question 151.

Which YANG construct is best suited to represent multiple interfaces where each entry has attributes such as name, state, and MTU?

1. list
   2. single leaf only
   3. typedef only
   4. revision statement only

Correct Answer: 1

Explanation:

A YANG list represents multiple instances of a repeated data structure. An interface list can contain entries identified by keys such as interface name, with each entry containing child leaves for MTU, administrative state, description, or other attributes. A single leaf cannot represent multiple structured interface records. Typedefs define reusable data types, while revision statements describe model-version history. Lists are fundamental when navigating model-driven network data because many resources naturally occur as repeated collections.

Question 152.

Which NETCONF operation is used specifically to retrieve configuration data from a chosen datastore?

1. <kill-session>
   2. <get-config>
   3. <close-session>
   4. <lock> only

Correct Answer: 2

Explanation:

The NETCONF <get-config> operation retrieves configuration data from a specified datastore such as running or candidate, depending on device support. This differs from <get>, which can retrieve both configuration and operational state information. Filters can be included to reduce the amount of returned data. <lock> reserves a datastore, while <close-session> and <kill-session> manage NETCONF sessions. Selecting the correct retrieval operation helps automation obtain only the required information.

Question 153.

Which NETCONF operation is commonly used to change configuration data in a target datastore?

1. <edit-config>
   2. <ping>
   3. <traceroute>
   4. <discover>

Correct Answer: 1

Explanation:

The NETCONF <edit-config> operation modifies configuration in a specified target datastore. The request contains structured configuration data and may include operation attributes describing whether objects should be merged, replaced, created, or deleted. Supported datastore behavior varies by device. NETCONF also provides operations for retrieval, locking, validation, and committing changes where supported. Commands such as ping and traceroute are operational utilities and are not standard NETCONF configuration-editing RPCs.

Question 154.

Which NETCONF capability allows configuration changes to be prepared before they are activated on a device?

1. Running datastore only
   2. Candidate datastore
   3. Syslog buffer
   4. ARP cache

Correct Answer: 2

Explanation:

When supported, the candidate datastore allows automation to prepare configuration changes separately from the active running configuration. The client can edit candidate, review or validate the changes, and then commit them to make them active. This can reduce risk when multiple related modifications must be applied together. Not every platform supports candidate configuration, so automation should inspect NETCONF capabilities before assuming it is available. Syslog and ARP information are unrelated to configuration staging.

Question 155.

Which NETCONF operation normally activates candidate configuration changes after they have been prepared?

1. <commit>
   2. <get>
   3. <lock>
   4. <close-session>

Correct Answer: 1

Explanation:

The <commit> operation activates changes made in the candidate datastore by applying them to the running configuration, when the platform supports the candidate capability. This makes it possible to stage several configuration changes before activating them together. <get> retrieves information, <lock> reserves a datastore against conflicting edits, and <close-session> ends the management session. Automation should validate changes before committing whenever possible, particularly in production environments.

Question 156.

Which RESTCONF method is commonly used to retrieve YANG-modeled data?

1. POST only
   2. DELETE
   3. PATCH only
   4. GET

Correct Answer: 4

Explanation:

RESTCONF uses HTTP methods, and GET is used to retrieve YANG-modeled configuration or operational data. Depending on the requested URI, the response may contain containers, lists, leaves, or other modeled structures. JSON is commonly used, though XML can also be supported. POST, PUT, PATCH, and DELETE are associated with creating or modifying resources as defined by RESTCONF semantics. Using GET for retrieval allows automation to inspect current state before determining whether configuration changes are required.

Question 157.

Which development practice is most useful for checking whether a generated configuration matches the expected output before sending it to a device?

1. Unit testing
   2. Disable all validation
   3. Test directly on every production device first
   4. Remove source-control history

Correct Answer: 1

Explanation:

Unit testing can validate functions or templates that generate configuration before that configuration reaches a device. A test can provide known input variables and compare the generated result with an expected output. This helps identify formatting problems, incorrect logic, missing fields, or unintended values. Testing does not replace integration testing, but it catches many errors early and can be run automatically in CI. Production-first testing increases risk, while removing validation and history eliminates useful safeguards.

Question 158.

Which type of test verifies that several automation components work together correctly with an API or simulated infrastructure system?

1. Unit test only
   2. Integration test
   3. Spell check
   4. Static route test only

Correct Answer: 2

Explanation:

Integration testing evaluates how multiple components interact, such as a Python function communicating with an API, parsing the result, and passing data into another module. It may use a lab controller, mock service, simulator, or controlled infrastructure. Unit tests focus on smaller isolated components, while integration tests reveal problems involving authentication, data formats, dependencies, or API behavior. In infrastructure automation, both types of testing are valuable because correct individual functions do not guarantee that the complete workflow behaves correctly.

Question 159.

Which CI pipeline step would best detect Python style and common code-quality problems before merge?

1. Linting
   2. Packet capture
   3. VLAN creation
   4. Routing convergence

Correct Answer: 1

Explanation:

Linting analyzes source code for style problems, suspicious constructs, and common programming errors. Python linters can identify issues such as unused imports, undefined variables, formatting inconsistencies, and some classes of logical mistakes. Linting does not replace tests, but it provides a fast automated quality check that can run on every code change. Packet capture, VLAN creation, and routing convergence are infrastructure operations rather than software-quality checks. Combining linting with unit tests and code review improves automation reliability.

Question 160.

A team wants an automation pipeline to stop automatically if a test fails instead of continuing to production deployment. Which design principle should the pipeline use?

1. Ignore failed stages
   2. Deploy first and test later
   3. Use quality gates that block promotion when validation fails
   4. Disable test reporting

Correct Answer: 3

Explanation:

Quality gates enforce defined conditions that must be satisfied before a change can proceed to the next stage. If unit tests, validation, security checks, or policy checks fail, the pipeline should stop rather than promoting potentially defective automation into production. This creates a controlled CI/CD process and reduces the chance of widespread infrastructure impact. Testing after deployment defeats much of the value of continuous integration. Quality gates should be paired with useful failure reporting so engineers can quickly identify and correct the underlying problem.