350-401 Automation Practice Question
A network engineer is using the YANG Suite tool to explore YANG models on a Cisco IOS XE device. The engineer wants to retrieve the operational state of all interfaces using NETCONF. The engineer sends a <get> RPC with a filter that selects the 'interfaces-state' container from the ietf-interfaces YANG module. The device returns an empty response. The engineer confirms that interfaces are up and running. What is the most likely reason for the empty response?
⚠ Common exam trap
The trap here is assuming that the 'interfaces-state' container still exists in all implementations, when it has been deprecated in newer YANG models.
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 'interfaces-state' container is deprecated in favor of the 'interfaces' container with 'config false' nodes.
The ietf-interfaces YANG module has evolved. In RFC 8343, the 'interfaces-state' container was deprecated and its contents merged into the 'interfaces' container. State data is now represented as 'config false' nodes within the same tree. If a device implements the newer revision, a filter for 'interfaces-state' will not match any data, resulting in an empty response. The engineer should adjust the filter to target the 'interfaces' container and look for state nodes.
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 'interfaces-state' container is deprecated in favor of the 'interfaces' container with 'config false' nodes.
Why this is correct
In newer revisions of the ietf-interfaces YANG module (RFC 8343), the 'interfaces-state' container was removed and replaced by the 'interfaces' container containing both configuration and state data, with state nodes marked as 'config false'. If the device implements the newer model, a filter targeting 'interfaces-state' will return no data. The engineer should query the 'interfaces' container instead.
- ✗
The ietf-interfaces YANG module is not supported by the device.
Why it's wrong here
Cisco IOS XE supports the ietf-interfaces YANG module, and it is commonly used for interface configuration and state. If the module were unsupported, the device would likely return an error indicating an unknown module, rather than an empty response. The engineer should verify the supported YANG modules using the 'show netconf-yang modules' command.
- ✗
The NETCONF session is using the 'candidate' datastore, which does not contain operational data.
Why it's wrong here
The 'candidate' datastore holds configuration data, not operational state. However, a <get> RPC retrieves data from the running datastore by default, not the candidate. If the engineer explicitly specified the candidate datastore, operational state would not be available. But the scenario does not indicate that; the issue is more likely due to the YANG model revision.
- ✗
The filter is using the wrong namespace for the ietf-interfaces module.
Why it's wrong here
An incorrect namespace would typically cause a parsing error or an empty response if the filter doesn't match any data. However, the engineer is using the standard ietf-interfaces namespace, which is urn:ietf:params:xml:ns:yang:ietf-interfaces. This is correct. The issue is more likely related to the data model structure or the use of the wrong datastore.
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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 350-401 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 350-401 exam.