200-901 Network Fundamentals Practice Question
A developer is writing a script that uses the Cisco SD-WAN vManage REST API to retrieve a list of devices. The script uses the GET method to https://vmanage.example.com/dataservice/device. The API returns a 401 Unauthorized status code. Which of the following should the developer do to resolve the issue?
⚠ Common exam trap
The trap here is assuming that a 401 error is related to the request format or URL, when it specifically indicates missing or invalid authentication credentials.
Answer choices
Why each option matters
Answer the question above first, then reveal the full breakdown to understand why each option is right or wrong.
Correct answer & explanation
✓
Include a valid authentication token in the request header.
The 401 Unauthorized status code indicates that the request lacks valid authentication credentials. For the Cisco SD-WAN vManage API, developers must authenticate first, usually by obtaining a session token, and then include that token in subsequent requests. Without it, the API rejects the request. The other options address different issues such as method, TLS, or query parameters, which would produce different error codes.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
Ensure the request URL includes the correct query parameters for device filtering.
Why it's wrong here
Incorrect query parameters would not cause a 401 Unauthorized error. They might result in a 400 Bad Request or a 200 OK with filtered results. The 401 specifically points to missing or invalid authentication, so the developer must focus on providing valid credentials rather than adjusting query parameters.
- ✓
Include a valid authentication token in the request header.
Why this is correct
A 401 Unauthorized response means the request lacks valid authentication credentials. The vManage API requires a session token or basic authentication. The developer should obtain a token by authenticating to the /j_security_check endpoint or using basic auth, then include it in the request header, typically as a cookie (JSESSIONID) or an Authorization header. This will allow the request to succeed.
- ✗
Verify that the vManage server's TLS certificate is trusted by the client.
Why it's wrong here
A TLS certificate issue would typically result in an SSL/TLS handshake failure or a certificate validation error, not an HTTP 401 status code. The 401 is an application-layer response indicating authentication failure. While certificate trust is important for secure communication, it is not the cause of a 401 error.
- ✗
Change the HTTP method to POST.
Why it's wrong here
The 401 status code indicates an authentication failure, not an issue with the HTTP method. Changing to POST would not resolve authentication problems and would likely cause a different error, such as 405 Method Not Allowed, if the endpoint does not support POST. The developer needs to address authentication credentials instead.
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JA
Written and reviewed by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
Last reviewed September 2026 · checked against the official Cisco exam blueprint
This 200-901 practice question is part of Courseiva's free Cisco certification practice question bank. Courseiva provides original exam-style practice questions with explanations, topic-based practice, mock exams, readiness tracking, and study analytics to help learners prepare for the 200-901 exam.