Free Practice Questions for Cisco 200-901 Exam

Cisco IOS XE supports model-driven programmability using protocols such as gNMI (gRPC Network Management Interface). gNMI is a protocol that provides a way to manage and configure network devices using a standardized approach to data models and APIs.

Model-Driven Telemetry: gNMI is used for streaming telemetry data from network devices.

Configuration Management: It allows for the configuration of network devices using standardized YANG models.

In the Bash shell, the output of a command can be redirected to a file using the > operator. This operator takes the standard output (stdout) of the command and writes it to the specified file.

Option B (devnet > output.txt): This redirects the output of the devnet command to a file named output.txt.

Option A (devnet & output.txt): This is not a valid redirection operator.

Option C (devnet < output.txt): This uses the file output.txt as input to the devnet command, which is not the requirement.

Option D (devnet I output.txt): This is not a valid redirection operator.

Synchronous API Operations:

Immediate Response: In a synchronous operation, the client sends a request to the server and waits for an immediate response. The client cannot proceed until it receives this response.

Blocking Call: The call is considered blocking, meaning the client application is blocked from performing other tasks until the response is received.

Use Case: This is useful when the result of the operation is required immediately to continue the workflow.

Asynchronous API Operations:

Delayed Response: In an asynchronous operation, the client sends a request to the server and does not wait for an immediate response. Instead, it continues its processing and can check back later for the result.

Non-blocking Call: The call is non-blocking, allowing the client to perform other tasks while waiting for the server to complete the operation.

Polling and Webhooks: Clients may poll the server for status updates or subscribe to a webhook to be notified when the operation is complete.

Task ID: The server may provide a task ID in the response that can be used to check the status of the operation later.

References:

Cisco DevNet API Documentation: API Design Guide

A version control system (VCS) is essential for managing changes to source code over time. One significant advantage of a VCS is:

Facilitates resolving conflicts when merging code (Option C):

Version control systems like Git track changes made by different developers and provide tools to manage and merge these changes. When multiple developers work on the same codebase, conflicts can arise if they make changes to the same lines of code. A VCS helps in identifying these conflicts and provides mechanisms to resolve them, ensuring that the final merged code is consistent and error-free.

References:

Git Documentation on Merging

Cisco DevNet Version Control Systems

The task is to determine which command correctly outputs the page_id value from the JSON payload shown in the Python 3.7 script. Let’s analyze the options and the payload structure to verify the correct answer.

JSON Payload Analysis:

The JSON payload provided in the exhibit shows that items is a key in the top-level dictionary.

The value of items is a list of dictionaries, and each dictionary contains various keys, including page_id.

Code Analysis:

The JSON data returned by the get_json function is assigned to the variable items.

The goal is to access the page_id key within the first dictionary of the list associated with the items key.

Options Analysis:

Option A: print(items['items']['page_id'])

This will not work because items['items'] is a list, not a dictionary. Attempting to access ['page_id'] directly from a list will result in a TypeError.

Option B: print(items.get('items').get('page_id'))

This will also not work for the same reason as Option A. items.get('items') returns a list, and calling .get('page_id') on a list is invalid.

Option C: print(items.get('items')[0].get('page_id'))

This is correct. items.get('items') returns the list, [0] accesses the first element of the list (which is a dictionary), and .get('page_id') retrieves the value of the page_id key from that dictionary.

Option D: print(items['items']['page_id'].keys())

This will fail because items['items'] is a list and does not have a keys() method.

Correct Explanation:

The JSON structure contains a list under the key items.

To access page_id, we first need to get the first dictionary in this list ([0]).

We then access the page_id key in this dictionary.

Example:

print(items.get('items')[0].get('page_id'))

This code correctly navigates through the structure and retrieves the value associated with page_id.

References:

Python Documentation on Dictionaries: Python Docs

JSON Data Handling in Python: Python JSON

In the provided cURL command, the developer needs to include an authorization header with the access token to authenticate the API request. Without proper authentication, the server will reject the request and return an error code.

The HTTP call to create a room named "cisco" through the Webex API is returning a 400 Bad Request error because the body parameter is incorrect. The correct body parameter to create a room is "name" instead of "team".

A. Replace the team body parameter with the name body parameter - Correct. The correct parameter for creating a room is "name". B. Replace cisco with a valid name for a team - Incorrect. The issue is with the parameter name, not the value. C. Change the token in the header with the authorization token - Incorrect. The token appears to be correct since it is a 400 error and not a 401 Unauthorized error. D. Change the HTTP method of the call to PUT - Incorrect. The correct HTTP method for creating a room is POST.

References:

Cisco Webex API Documentation - Create a Room

Load balancers distribute network or application traffic across multiple servers to ensure no single server becomes overwhelmed. In modern application deployment, load balancers allow traffic to continue smoothly as new compute units are brought online and old units are decommissioned. This ensures high availability and reliability of services.

In the provided Python script, database credentials (DB_USER, DB_PWD) are stored in a JSON configuration file (config.json). While it is common to store configuration and credentials in external files, they should always be encrypted to ensure security.

Secret Management: Storing secrets such as database credentials directly in configuration files in plaintext is a security risk.

Encryption: Secrets must be encrypted to protect them from unauthorized access. This can be achieved using various methods such as encrypting the configuration file itself or using secret management tools.

Best Practices: Always ensure that sensitive information like passwords is encrypted when stored, especially in files that might be part of the source code.

Option C is the correct answer because it emphasizes the necessity of encrypting secrets if they are stored in the user database or configuration files to prevent unauthorized access.

In the provided network topology, Device E is positioned between Server 1 and Server 2. Device E, being a Layer 2 switch, will limit traffic between these servers by making forwarding decisions based on MAC addresses. If there are VLANs configured, Device E will ensure that traffic is segregated accordingly, allowing only specific traffic to pass between the servers as defined by the network policies.

References:

Cisco DevNet Associate Study Guide: Network Components (Chapter 2, Section: Switches and Their Role in Network Traffic Management).