CCNP Automation Practice Test 5 — 15 Questions

Question 1

A network engineer uses a Python script with the ncclient library to send a NETCONF <edit-config> RPC to a Cisco IOS XE router. The goal is to add a new loopback interface with a specific IP address. The script sends the RPC with the default-operation set to 'merge'. The router returns an 'ok' response, but the configuration is not applied. The engineer verifies the XML payload is well-formed and the interface does not already exist. What is the most likely reason the configuration was not applied?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

The NETCONF session must be in candidate datastore mode, and the configuration must be committed with after .. Cisco IOS XE NETCONF supports the candidate datastore, where configuration changes are staged and require an explicit RPC to become active. If the script sends targeting the candidate datastore without a subsequent , the router acknowledges the RPC with 'ok' but the running configuration remains unchanged. To apply changes immediately, the script should either target the running datastore or include a operation after editing the candidate.

Answer

The <edit-config> RPC requires the 'default-operation' to be set to 'replace' for new interface creation.

Answer

The NETCONF username lacks the necessary privileges to modify the running configuration, so the change is silently ignored.

Answer

The XML payload must include the 'nc:operation' attribute set to 'create' for new interfaces.

Question 2

A network automation engineer is comparing YANG models and their usage in NETCONF and RESTCONF on Cisco IOS XE devices. Which two statements are true about YANG models in this context? (Choose two.)

Accepted Answer

YANG models define the data structure and semantics for configuration and state data.. YANG is a data modeling language that defines the structure and semantics of configuration and state data. It is used by both NETCONF and RESTCONF on Cisco IOS XE, allowing the same models to be accessed via different protocols. The other statements are incorrect: YANG is not limited to specific IOS XE versions, is not written in XML, and does not define RPC methods. These two true statements highlight YANG's role as a protocol-agnostic model.

Answer

YANG models are only supported on devices running Cisco IOS XE 16.12 or later.

Answer

YANG models are written in XML and must be converted to JSON for RESTCONF.

Answer

YANG models define how NETCONF and RESTCONF operations are performed, including RPC methods.

Question 3

A network engineer is designing a Python script to interact with a Cisco IOS XE device using RESTCONF. The script must support both configuration and operational data retrieval. Which two HTTP methods are required to accomplish these tasks? (Choose two.)

Accepted Answer

PATCH. To retrieve operational data and configuration data, the script must use GET. To modify configuration, it must use a method like PATCH, which allows partial updates. POST and PUT are also configuration methods but are not strictly required for the described tasks, as PATCH can handle most modifications. DELETE is for removal. Therefore, GET and PATCH are the two essential methods.

Answer

PUT

Answer

DELETE

Answer

POST

Question 4

A network engineer is using the Python ncclient library to configure a Cisco IOS XE device via NETCONF. The engineer wants to ensure that the configuration change is applied atomically and can be rolled back if it fails. Which NETCONF capability should be used to achieve this?

Accepted Answer

candidate. The candidate datastore capability in NETCONF allows configuration changes to be staged and then committed atomically. If the commit fails, the candidate can be rolled back or discarded. This provides the transactional integrity required. Other capabilities like confirmed-commit and rollback-on-error are extensions that enhance rollback but depend on the candidate datastore for atomic editing.

Answer

rollback-on-error

Answer

writable-running

Answer

confirmed-commit

Question 5

A network engineer is using a Python script with the requests library to interact with a Cisco IOS XE device's RESTCONF API. The script sends a PATCH request to update the description of a loopback interface. The request returns HTTP 204 No Content, but when the engineer checks the device, the description has not changed. The engineer verifies that the YANG model path is correct and the payload is valid JSON. What is the most likely cause of this issue?

Accepted Answer

The PATCH request must include the 'Content-Type' header set to 'application/yang-data+json'.. When sending a PATCH request with a JSON payload to a RESTCONF API, the 'Content-Type' header must be set to 'application/yang-data+json' to indicate the payload format. Without this header, the server may not parse the payload correctly, resulting in no change despite a 204 response. The 204 status means the request was successful, but if the payload was ignored, the configuration remains unchanged. Ensuring the correct 'Content-Type' header is essential for the server to interpret and apply the update.

Answer

The PATCH method is not supported by RESTCONF; the engineer should use PUT instead.

Answer

The request URL must end with a trailing slash to indicate the resource to be modified.

Answer

The device's RESTCONF implementation requires the 'Accept' header to be set to 'application/yang-data+json' for PATCH requests.

Question 6

A network automation team uses Ansible to manage a fleet of Cisco IOS XE devices. They have a playbook that uses the 'ios_config' module to push a banner. The playbook runs successfully but does not report any changes, even though the banner is different on the devices. The engineer checks the device and sees the old banner. What is the most likely cause?

Accepted Answer

The 'ios_config' module uses the 'lines' parameter to specify configuration, but the banner text contains special characters that cause the comparison to fail.. The 'ios_config' module determines whether changes are needed by checking if the desired configuration lines are already present in the running config. It uses regex matching, so special characters in banner text can cause false positives, making the module think the configuration is already correct. The other options are either irrelevant or would produce different symptoms.

Answer

The 'ios_config' module requires the 'backup' option to be set to 'yes' to detect changes.

Answer

The playbook is using the 'ios_command' module instead of 'ios_config' to push configuration.

Answer

The banner configuration lines are not idempotent, so the module always considers them changed and skips them.

Question 7

A network automation engineer is deploying a Python script that uses the ncclient library to configure a Cisco IOS XE device via NETCONF over SSH. The script successfully retrieves interface statistics but fails when attempting to modify the MTU on a GigabitEthernet interface. The engineer verifies that the NETCONF session is established and the device supports the ietf-interfaces YANG model. Which action should the engineer take to resolve the configuration failure?

Accepted Answer

Enable the NETCONF-YANG feature on the device using the netconf-yang command in global configuration mode.. The NETCONF-YANG feature must be enabled on Cisco IOS XE devices to allow configuration changes via NETCONF. Read operations may work without it, but write operations require the feature. Enabling it with the netconf-yang global configuration command resolves the issue. This is a fundamental step in setting up NETCONF automation on Cisco devices.

Answer

Ensure the YANG model for ietf-interfaces is installed on the device by copying it to the bootflash and loading it with the yang-module command.

Answer

Change the SSH port used by ncclient from 22 to 830, as NETCONF only listens on port 830.

Answer

Modify the script to use the edit-config operation with the default-operation attribute set to 'merge' instead of 'replace'.

Question 8

A network automation team is using Ansible to manage a fleet of Cisco IOS XE devices. The team wants to ensure that a configuration change is applied only if the device is reachable and the change is not already present. Which Ansible module and parameter combination achieves this idempotent behavior?

Accepted Answer

ios_config with the 'lines' parameter containing the desired configuration. The ios_config module is inherently idempotent when the desired configuration is specified in the 'lines' parameter. It compares the desired lines against the running configuration and only applies them if they are missing. This satisfies the requirement to apply changes only when needed, and the module verifies device reachability before attempting to connect.

Answer

ios_command with the 'wait_for' parameter to verify connectivity

Answer

ios_config with the 'save' parameter set to yes and 'diff_against' set to running

Answer

ios_config with the 'backup' parameter set to yes

Question 9

A network automation engineer is using Cisco IOS XE RESTCONF to manage device configuration. The engineer wants to ensure that the RESTCONF API is properly secured and that only authorized users can access it. Which two configurations are required to enable secure RESTCONF access on a Cisco IOS XE device? (Choose two.)

Accepted Answer

Enable the RESTCONF API using the 'restconf' global configuration command.. To enable secure RESTCONF access on Cisco IOS XE, two key configurations are required: enabling the RESTCONF API with the 'restconf' command and enabling HTTPS with the 'ip http secure-server' command. The 'restconf' command activates the RESTCONF service, while 'ip http secure-server' provides the secure transport. Without both, RESTCONF will not be accessible securely. Other options like NETCONF enablement or ACLs are not required for basic RESTCONF functionality.

Answer

Enable the NETCONF protocol using the 'netconf-yang' command.

Answer

Configure a username and privilege level 15 using the 'username' command.

Answer

Configure an ACL to permit only HTTPS traffic to the device.

Question 10

A network engineer is using the Cisco SD-WAN vManage REST API to automate the creation of a new VPN template. The engineer sends a POST request to /dataservice/template/feature with a JSON payload. The API returns HTTP 200 OK but the template is not created. What is the most likely cause of this behavior?

Accepted Answer

The payload is missing the required 'templateType' field or contains an invalid value, causing the API to accept the request but not persist the template.. The Cisco SD-WAN vManage REST API can return HTTP 200 OK even when a template is not created due to missing required fields like 'templateType'. The API may not enforce strict validation, so the engineer must verify the response body and check the template list. This behavior is specific to certain API endpoints and versions, making it a subtle troubleshooting point.

Answer

The API requires the template to be created in two steps: first create the feature template, then attach it to a device template.

Answer

The POST request must include the header 'Content-Type: application/json' and a valid X-XSRF-TOKEN.

Answer

The JSON payload contains a syntax error that the API silently ignores, returning a success code without processing.

Question 11

A network engineer is designing a NETCONF-based automation solution for a Cisco IOS XE device. The engineer needs to retrieve interface statistics and configure an interface description. Which two actions must be performed to establish a NETCONF session and perform these operations? (Choose two.)

Accepted Answer

Enable the NETCONF-YANG feature on the device using the 'netconf-yang' command in global configuration mode.. To use NETCONF on Cisco IOS XE, the NETCONF-YANG feature must be enabled, and the appropriate YANG models must be available to structure the data. The other options are either not mandatory or are client-side choices. Enabling NETCONF-YANG starts the SSH server on port 830 and allows the device to process NETCONF RPCs.

Answer

Open TCP port 830 on the device's firewall to allow NETCONF traffic.

Answer

Configure an SSH user with privilege level 15 and ensure the 'aaa new-model' is enabled.

Answer

Use the 'ncclient' Python library to send RPCs over the NETCONF session.

Question 12

A network engineer writes a Python script to retrieve the operational status of all interfaces from a Cisco IOS XE router. The script sends a GET request to https://10.1.1.1/restconf/data/ietf-interfaces:interfaces-state but receives an HTTP 404 Not Found error, even though the RESTCONF API is enabled and the interface data exists. The engineer verifies that the authentication credentials are correct. What is the most likely cause of the 404 error?

Accepted Answer

The URI should use the ietf-interfaces module without the -state suffix, as the -state suffix is not a valid module name in this IOS XE release.. A 404 error indicates that the requested URI is not found. In Cisco IOS XE RESTCONF implementations, the ietf-interfaces-state module is often not a separate module; instead, operational state is included within the ietf-interfaces module or exposed differently. The engineer should query the YANG library to discover supported modules and correct URIs.

Answer

The correct URI should be /restconf/data/ietf-interfaces:interfaces-state/interface, not the base path without the list node.

Answer

The RESTCONF API requires the client to include an Accept header specifying application/yang-data+json.

Answer

The ietf-interfaces module is not supported in this IOS XE release; the correct module for interface state data is ietf-interfaces-state.

Question 13

A network automation engineer uses NETCONF over SSH to configure a Cisco IOS XE device. The engineer sends an RPC with a default-operation of 'merge' to add a new loopback interface. The device responds with an containing 'operation-failed' and a message that the interface already exists. However, the engineer confirms that the loopback interface is not present in the running configuration. What is the most likely reason for this error?

Accepted Answer

The interface name in the NETCONF payload does not match the expected YANG key format, causing the server to misinterpret the request and incorrectly report an existing interface.. The error 'operation-failed' with a message that the interface already exists, despite the interface not being in the running configuration, often stems from a mismatch in the interface name key. YANG models for interfaces use a list keyed by name, and the exact string must match the device's expected format. A case mismatch or incorrect prefix can cause the server to misinterpret the request.

Answer

The NETCONF server is configured with the 'with-defaults' capability set to 'report-all', causing the server to consider default interfaces as existing, even if not explicitly configured.

Answer

The YANG model for interfaces uses a list keyed by name, and the merge operation attempts to create a new list entry with the same key as an existing entry, but the existing entry is in a different datastore or is hidden.

Answer

The NETCONF session is using the candidate datastore, but the candidate has not been committed, so the running configuration does not reflect the new interface.

Question 14

A network engineer is using a Python script with the 'requests' library to send a RESTCONF PATCH request to a Cisco IOS XE device to update the description of GigabitEthernet1. The script uses the URL https://192.168.1.1/restconf/data/ietf-interfaces:interfaces/interface=GigabitEthernet1 and includes the JSON payload with the new description. The request returns HTTP 204 No Content, but the description is not updated on the device. What is the most likely reason?

Accepted Answer

The JSON payload is structured incorrectly; it must include the 'ietf-interfaces:interface' container and the 'description' leaf with the correct hierarchy.. A 204 No Content response indicates the server successfully processed the request but did not return any content. If the configuration did not change, the most likely cause is that the JSON payload did not conform to the expected YANG structure, so the server ignored the data. The engineer must ensure the payload exactly matches the model, including the top-level container 'ietf-interfaces:interfaces' and the correct nesting.

Answer

The interface name in the URL should be 'GigabitEthernet1' but the actual interface name is 'GigabitEthernet1/0/1'.

Answer

The 'Content-Type' header is missing or set incorrectly; it should be 'application/yang-data+json'.

Answer

The PATCH method is not supported by RESTCONF; the engineer should use PUT instead.

Question 15

A network engineer is designing a Python script that uses the requests library to interact with a Cisco IOS XE device's RESTCONF API. The engineer wants to ensure the script can handle authentication and retrieve data in JSON format. Which two actions must the engineer take to successfully authenticate and receive JSON responses? (Choose two.)

Accepted Answer

Include a basic authentication header with the username and password encoded in Base64.. To authenticate to Cisco IOS XE RESTCONF, the script must include an Authorization header with Basic authentication credentials. To receive JSON, it must set the Accept header to application/yang-data+json. These two actions are required for successful authentication and JSON response retrieval.

Answer

Use the POST method to retrieve interface statistics from the RESTCONF API.

Answer

Configure the device with the 'restconf' command under global configuration to enable the API.

Answer

Include a custom header 'X-Auth-Token' with a token obtained from a prior authentication request.