200-901 Infrastructure and Automation Practice Test 5 — 15 Questions

Question 1

A DevOps engineer is implementing Infrastructure as Code (IaC) for network devices. Which of the following practices is most critical to ensure that the environment state matches the desired configuration defined in code?

Accepted Answer

Ensuring that the automation tool is idempotent.. Idempotency ensures that applying the same configuration multiple times always results in the same desired state, regardless of the current state of the device. This is the most critical practice for IaC because it prevents configuration drift and guarantees that the environment state matches the code-defined configuration. Without idempotency, repeated runs of the automation tool could introduce unintended changes or fail to correct deviations.

Answer

Using Jinja2 templates to generate device configurations.

Answer

Using version control for all configuration files.

Answer

Implementing rollback procedures for failed deployments.

Question 2

A network engineer attempts to use RESTCONF to retrieve the running configuration of a Cisco IOS XE device. The GET request to '/restconf/data/Cisco-IOS-XE-native:native' returns a 405 Method Not Allowed error. What is the most likely cause?

Accepted Answer

RESTCONF is not enabled or the YANG module is not supported.. A 405 Method Not Allowed error indicates that the HTTP method (GET) is not supported for the requested resource. In RESTCONF, this typically occurs when the RESTCONF service is not enabled on the device or the specific YANG module (Cisco-IOS-XE-native) is not supported or loaded. Without the service or module, the server cannot process the GET request for the running configuration.

Answer

The API key provided is invalid.

Answer

The request body was malformed.

Answer

The device does not support HTTPS.

Question 3

In a Python script using the 'requests' library to interact with Cisco DNA Center API, which function call is used to send a POST request with JSON data?

Accepted Answer

requests.post(url, json=data). Option A is correct because the `requests.post()` function is specifically designed to send HTTP POST requests, and passing the `json=data` parameter automatically serializes the Python dictionary to JSON and sets the `Content-Type` header to `application/json`. This is the standard way to create a resource via Cisco DNA Center's REST API endpoints that expect JSON payloads.

Answer

requests.patch(url, json=data)

Answer

requests.get(url, json=data)

Answer

requests.put(url, json=data)

Question 4

A team uses Chef to manage network device configurations. Which component of Chef is responsible for storing configuration policy and distributing it to nodes?

Accepted Answer

Chef Server. The Chef Server is the central hub that stores configuration policies (cookbooks, roles, environments, data bags) and distributes them to nodes via a REST API. When a Chef Client runs on a node, it authenticates with the Chef Server and downloads the relevant policy to converge the node to the desired state. This makes the Chef Server the authoritative source of configuration policy in a Chef architecture.

Answer

Knife

Answer

Chef Client

Answer

Supermarket

Question 5

When using NETCONF to edit the configuration of a Cisco IOS XE device, an engineer receives an <rpc-error> with error-tag 'in-use' and error-app-tag 'data-exists'. What does this error indicate?

Accepted Answer

The configuration being added already exists on the device.. The error-tag 'in-use' combined with the error-app-tag 'data-exists' in NETCONF indicates that the configuration operation (e.g., <edit-config> with operation 'create') attempted to add a configuration element that already exists in the running datastore. NETCONF uses these standardized error tags per RFC 6241 to signal that the requested operation cannot be completed because the target data node is already present, preventing duplicate configuration entries.

Answer

The NETCONF session was closed due to a timeout.

Answer

The RPC message was malformed.

Answer

The device does not have the required user permissions.

Question 6

Which TWO Ansible modules are commonly used for automating Cisco IOS devices?

Accepted Answer

ios_config. The `ios_config` module is correct because it is specifically designed to manage Cisco IOS device configurations by sending configuration commands via SSH or Telnet, using the CLI to apply changes to the running or startup configuration. This module is part of Ansible's `cisco.ios` collection and directly supports the IOS operating system, making it the standard choice for automating configuration tasks on Cisco IOS devices.

Answer

junos_config

Answer

nxos_command

Answer

eos_config

Question 7

Which THREE of the following are key principles of Infrastructure as Code (IaC) as applied to network automation?

Accepted Answer

Configuration should be idempotent.. IaC principles include idempotency (repeatable results), version control (track changes), and continuous testing (validate configurations). Option A (manual configuration) is opposite. Option D (temporary scripts) is not a principle.

Answer

Manual configuration is preferred for critical devices.

Answer

Temporary scripts should be used for one-time changes.

Question 8

A network automation engineer uses Ansible to manage a group of Cisco IOS XE devices. The playbook fails with 'unreachable' for some devices. Which TWO actions should the engineer take to troubleshoot the connectivity?

Accepted Answer

Use the 'ios_command' module to test connectivity.. Option C is correct because the 'ios_command' module can be used to verify basic connectivity by sending a simple command (e.g., 'show version') to the device. If the module returns a response, it confirms that Ansible can reach the device and that the credentials are valid, isolating the issue to the specific task or playbook logic rather than connectivity.

Answer

Increase the timeout value in the playbook.

Answer

Ignore the unreachable devices and proceed.

Answer

Check if SNMP is enabled on the devices.

Question 9

A NETCONF RPC reply indicates a validation failure. Based on the exhibit, what is the most probable reason for the failure?

Accepted Answer

The MTU value provided is outside the allowed range.. The NETCONF RPC reply indicates a validation failure, which typically occurs when the data being configured does not conform to the YANG model's constraints. In this context, the MTU value provided is outside the allowed range defined in the YANG model for the interface, triggering a validation error before any configuration is applied.

Answer

The XML syntax in the edit operation was malformed.

Answer

The XML namespace 'Cisco-IOS-XE-native' is not supported.

Answer

The NETCONF session timed out before the operation completed.

Question 10

A network engineer wants to programmatically enable an interface using the YANG model shown. Which XPath expression correctly targets the 'shutdown' leaf for GigabitEthernet0/1?

Accepted Answer

/interfaces/GigabitEthernet[name='0/1']/shutdown. Option B is correct because it uses the correct XPath syntax to target the 'shutdown' leaf under a specific GigabitEthernet interface instance. The path starts from the root, navigates to the 'interfaces' container, selects the 'GigabitEthernet' list entry where the 'name' key equals '0/1', and then accesses the 'shutdown' leaf. This matches the YANG model structure where list entries are filtered using a predicate with the key leaf.

Answer

//shut

Answer

/Cisco-IOS-XE-interface:interfaces/GigabitEthernet[0/1]/shutdown

Answer

/native/interface/GigabitEthernet0/1/shutdown

Question 11

A developer uses the Cisco DNA Center API to retrieve device inventory. The JSON response is shown. Which Python code snippet correctly extracts the serial number?

Accepted Answer

data['response'][0]['serialNumber']. Option A is correct because the JSON response from the Cisco DNA Center device inventory API returns a list of devices under the 'response' key, and each device is a dictionary. The serial number for the first device is accessed by indexing into the list with [0] and then retrieving the 'serialNumber' key from that dictionary.

Answer

data['serialNumber']

Answer

data['response']['serialNumber']

Answer

data[0]['serialNumber']

Question 12

An engineer needs to modify the running configuration of a Cisco IOS-XE device using a protocol that is stateless and uses HTTP methods. Which protocol should be used?

Accepted Answer

RESTCONF. RESTCONF is the correct choice because it is a stateless protocol that uses standard HTTP methods (GET, POST, PUT, PATCH, DELETE) to manipulate YANG-defined data stores on a Cisco IOS-XE device. Unlike NETCONF, which is stateful and session-oriented, RESTCONF operates over HTTP without maintaining session state, making it ideal for lightweight, RESTful automation.

Answer

NETCONF

Answer

SNMP

Answer

CLI

Question 13

A network automation engineer is writing an Ansible playbook to configure interface descriptions on Cisco IOS-XE devices. The playbook uses the ios_config module. Which attribute should be used to ensure idempotency and only apply changes when the interface does not already have the desired description?

Accepted Answer

lines. Option A is correct because the `lines` attribute in the `ios_config` module specifies the exact configuration lines to be applied. Ansible's `ios_config` module inherently checks the current device configuration against the desired state defined in `lines`; if the interface already has the matching description, the module skips the task, ensuring idempotency. This prevents unnecessary configuration changes and maintains network stability.

Answer

src

Answer

parents

Answer

before

Question 14

A Cisco DevNet engineer is configuring model-driven telemetry on a Cisco IOS-XE device. The telemetry subscription includes the following path: 'Cisco-IOS-XE-native:native/interface/GigabitEthernet[Name='1/0/1']/ip/address'. Which part of this path identifies a specific list instance?

Accepted Answer

[Name='1/0/1']. Option B is correct because the XPath expression `[Name='1/0/1']` is a predicate filter that selects a specific list instance from the `GigabitEthernet` YANG list. In YANG model-driven telemetry, list keys are used to identify individual entries, and the predicate syntax `[key='value']` pinpoints exactly one instance within the list.

Answer

Cisco-IOS-XE-native

Answer

GigabitEthernet

Answer

ip/address

Question 15

Refer to the exhibit. Based on the output, which interface is experiencing a Layer 2 issue?

Accepted Answer

Serial0/0/0. The output shows that Serial0/0/0 is in the 'down/down' state, which indicates a Layer 1 or Layer 2 issue. Since the serial interface is administratively up (not 'administratively down'), the 'down/down' status points to a Layer 2 problem, such as a missing keepalive, encapsulation mismatch, or loss of carrier detect (CD) signal, rather than a Layer 3 addressing or routing issue.

Answer

Loopback0

Answer

GigabitEthernet1

Answer

GigabitEthernet2