350-501 Automation and Assurance Practice Question
An engineer is using RESTCONF to configure an interface on a Cisco IOS-XE device. The request returns a 400 Bad Request error. What is the most likely cause?
⚠ Common exam trap
Cisco often tests the distinction between HTTP status codes in RESTCONF, where candidates confuse a 400 (client payload error) with a 404 (resource not found) or 401/403 (authentication/authorization), especially when the URI seems correct but the payload is invalid.
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
✓
The JSON payload contains incorrect data types or missing mandatory leafs
A 400 Bad Request in RESTCONF indicates a client-side error, typically malformed syntax. The most common cause is an invalid JSON payload, such as incorrect data types (e.g., string instead of integer) or missing mandatory leafs defined in the YANG module. RESTCONF validates the payload against the YANG schema before applying the configuration, and any schema violation triggers a 400 error.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
The device does not support RESTCONF
Why it's wrong here
If RESTCONF were not supported, the response would be 501 or 404, not 400.
- ✗
The user does not have sufficient privileges
Why it's wrong here
Insufficient privileges would result in a 401 or 403 error.
- ✗
The URI is incorrect
Why it's wrong here
An incorrect URI typically yields a 404 Not Found.
- ✗
The YANG module is not loaded
Why it's wrong here
YANG module not loaded would cause a 404 error, not 400.
- ✓
The JSON payload contains incorrect data types or missing mandatory leafs
Why this is correct
400 Bad Request indicates a client-side error; invalid payload is a common cause.
Go deeper
Related to this question
About these practice questions
This 350-501 question is part of Courseiva's 971-question bank — original exam-style content with full explanations and wrong-answer analysis, never real exam questions or exam dumps. Learn why practice questions differ from exam dumps →
JA
Written by Johnson Ajibi, MSc IT Security
Senior Network & Security Engineer · founder of Courseiva
This 350-501 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 350-501 exam.