hardMultiple Choice

200-901 Practice Question: A Python script using ncclient to configure a…

Exhibit

Refer to the exhibit.
from ncclient import manager

with manager.connect(
    host="10.0.0.1",
    port=830,
    username="admin",
    password="secret",
    hostkey_verify=False
) as m:
    config = '''
    <config>
      <native xmlns="http://cisco.com/ns/yang/Cisco-IOS-XE-native">
        <hostname>NewRouter</hostname>
      </native>
    </config>'''
    m.edit_config(target="running", config=config)

A Python script using ncclient to configure a Cisco IOS XE device fails with an error that the capability 'urn:ietf:params:xml:ns:netconf:base:1.0' is missing. What is the most likely cause?

⚠ Common exam trap

Cisco often tests the distinction between authentication/SSH errors and NETCONF capability negotiation errors, trapping candidates who confuse a missing capability with a credential or transport issue.

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 device does not have NETCONF enabled

The error indicates that the NETCONF base capability (urn:ietf:params:xml:ns:netconf:base:1.0) is not advertised by the device. This capability is mandatory for any NETCONF server; its absence means the device is not running a NETCONF server or NETCONF is not enabled. On Cisco IOS XE, NETCONF must be explicitly enabled via the 'netconf-yang' feature, and the error occurs when the ncclient client attempts to establish a session but the device does not respond with the required capability.

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 have NETCONF enabled
Why this is correct
The NETCONF subsystem must be explicitly enabled on Cisco IOS XE using the `netconf-yang` command before ncclient can connect. Without it, the device never advertises the base NETCONF 1.0 capability in its hello message, so the session fails during capability exchange. Enabling NETCONF satisfies the stem's missing-capability constraint.
✗
The username or password is incorrect
Why it's wrong here
Incorrect credentials produce an authentication failure, not a missing NETCONF base capability namespace. It tempts because login errors are a common cause of connection failures. The actual cause is that the device is not configured with "netconf-yang" or "netconf" enabled, so the base:1.0 capability is absent from its hello message.
✗
The edit-config operation should be on candidate instead of running
Why it's wrong here
The datastore choice affects edit-config targeting, not capability negotiation; base:1.0 is advertised in the server hello regardless of whether candidate or running is used. It is tempting because candidate datastores require the candidate capability, but that is a separate URN from base:1.0.
✗
The host key verification is disabled incorrectly
Why it's wrong here
Host key verification governs SSH server identity checking, not NETCONF capability advertisement; disabling it would not remove base:1.0 from the hello message. It is tempting because SSH misconfiguration causes connection failures, but the error here is specifically about a missing NETCONF capability URN.

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200-901 Practice Question: A Python script using ncclient to configure a…

Exhibit

Why each option matters

Option-by-option breakdown

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