350-401 Automation Practice Question
A network automation engineer is using the ncclient Python library to retrieve configuration from a Cisco IOS XE device via NETCONF. The engineer sends a <get-config> RPC with a filter for the interface configuration. The device returns a large XML response, but the engineer only needs the interface description and IP address. Which NETCONF capability should the engineer use to filter the response to only the required data?
⚠ Common exam trap
It's easy for candidates to confuse filtering capabilities with other NETCONF capabilities that deal with write operations or error handling, such as writable-running or rollback-on-error.
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
✓
urn:ietf:params:netconf:capability:subtree:1.0
NETCONF supports filtering of configuration data through capabilities. The subtree filtering capability allows a client to specify a filter that matches only the desired portions of the configuration tree. By using a subtree filter, the engineer can retrieve only the interface description and IP address, minimizing the response size and improving efficiency. Other capabilities like writable-running or rollback-on-error do not provide filtering.
Answer analysis
Option-by-option breakdown
For each option: why learners choose it and why it is or isn't the right answer here.
- ✓
urn:ietf:params:netconf:capability:subtree:1.0
Why this is correct
The subtree filtering capability allows the client to specify a filter that selects only the desired subtrees of the configuration data. By using a subtree filter, the engineer can request only the interface description and IP address, reducing the response size and processing. This is the standard way to filter NETCONF responses.
- ✗
urn:ietf:params:netconf:capability:xpath:1.0
Why it's wrong here
The xpath capability allows filtering using XPath expressions, which can select specific nodes. However, for subtree filtering as described, the subtree filtering capability is more directly suited. XPath is powerful but not the primary mechanism for subtree filtering in NETCONF; it is an optional capability that may not be supported by all devices.
- ✗
urn:ietf:params:netconf:capability:writable-running:1.0
Why it's wrong here
The writable-running capability indicates that the running configuration can be edited directly via NETCONF. It does not provide filtering capabilities. Using this capability would not help in reducing the response data; it only affects write operations, not read filtering.
- ✗
urn:ietf:params:netconf:capability:rollback-on-error:1.0
Why it's wrong here
The rollback-on-error capability ensures that if an error occurs during a configuration change, the device rolls back to the previous configuration. It is unrelated to filtering read operations. This capability does not affect the content of <get-config> responses.
Go deeper
Related to this question
Learn chapter
VLANs and Spanning Tree Protocol Concepts
Key term
NETCONF Protocol
NETCONF is a network management protocol that uses a structured data format to configure, retrieve, and modify network devices in a standard, programmatic way.
Key term
Cisco DNA Center Automation
Cisco DNA Center Automation is a centralized software platform that simplifies network management by automatically configuring, monitoring, and troubleshooting Cisco devices using policy-driven intent and software tools.
About these practice questions
This 350-401 question is part of Courseiva's 1,923-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 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.