easyMultiple ChoiceObjective-mapped
200-901 Practice Question: Refer to the exhibit
Exhibit
Refer to the exhibit.
{
"ietf-interfaces:interface": {
"name": "GigabitEthernet0/1",
"description": "Configured via NETCONF",
"type": "iana-if-type:ethernetCsmacd",
"enabled": true,
"ietf-ip:ipv4": {
"address": [
{
"ip": "192.0.2.1",
"netmask": "255.255.255.0"
}
]
}
}
}Refer to the exhibit. An engineer uses NETCONF to configure an interface. After applying this configuration, the interface is administratively up. However, the interface does not pass traffic. What is the most likely cause?
⚠ Common exam trap
Cisco often tests the distinction between CLI-style 'netmask' and YANG-model 'prefix-length' in NETCONF/RESTCONF questions, trapping candidates who assume the old CLI syntax works in model-driven APIs.
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 IP address configuration uses 'netmask' instead of 'prefix-length'
NETCONF uses YANG models that define IP address configuration with the leaf 'prefix-length' (an integer), not 'netmask'. The 'netmask' field is not a valid leaf in the standard ietf-interfaces or ietf-ip YANG model for IPv4 addresses, so the NETCONF server will either reject the configuration or apply it incorrectly, leaving the interface without a proper IP address and unable to pass traffic.
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 interface type is misspelled
Why it's wrong here
The type is valid.
- ✗
The 'enabled' field should be a string instead of a boolean
Why it's wrong here
Boolean is correct for JSON encoding of YANG boolean.
- ✓
The IP address configuration uses 'netmask' instead of 'prefix-length'
Why this is correct
The ietf-ip model requires prefix-length, not netmask.
- ✗
The interface name is invalid
Why it's wrong here
The name is valid.
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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.