mediumMultiple Choice
200-901 Practice Question: A developer is designing a Python script that…
A developer is designing a Python script that uses the NSO (Network Services Orchestrator) northbound API. Which data format is natively supported by NSO's RESTCONF API?
⚠ Common exam trap
Cisco often tests the misconception that RESTCONF only supports one format (typically JSON) because of its popularity in modern APIs, but the standard explicitly mandates support for both JSON and XML.
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
✓
JSON and XML
NSO's RESTCONF API natively supports both JSON and XML data formats, as defined by RFC 8040. RESTCONF uses HTTP methods to manipulate YANG-defined data, and the API can serialize data in either JSON (application/yang-data+json) or XML (application/yang-data+xml) based on the Accept header or Content-Type in the request. This dual-format support allows developers to choose the format that best fits their application's ecosystem.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✗
YAML only
Why it's wrong here
NSO's RESTCONF API exchanges data as JSON or XML, so a YAML-only client cannot parse or emit the payloads the server returns. YAML suits human-authored Ansible playbooks and configuration files, which is why it appears plausible here, but it is not a RESTCONF media type.
- ✗
JSON only
Why it's wrong here
RESTCONF negotiates either JSON or XML via the Content-Type and Accept headers, so restricting the script to JSON alone ignores the XML representation NSO also serves. JSON is the right pick when the client explicitly requests application/yang-data+json, not as the sole native format.
- ✗
XML only
Why it's wrong here
NSO's RESTCONF API serves both JSON and XML, so an XML-only client cannot consume JSON responses when the server negotiates that representation. XML is correct when the tooling or schema mapping demands it, but it is not the exclusive native format.
- ✓
JSON and XML
Why this is correct
NSO's RESTCONF northbound API natively supports both JSON and XML payloads, satisfying the requirement for formats the interface accepts without conversion. YAML is used for service models but is not a native RESTCONF media type.
Go deeper
Related to this question
About these practice questions
Courseiva writes every 200-901 question from scratch — 975 in total, each with an explanation and a wrong-answer breakdown. None are copied from real exams or 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 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.