JN0-224 sample questions

Question 1

A Python script using PyEZ needs to retrieve the BGP summary information and then process only the neighbors that are in the 'Established' state. Given that `dev.rpc.get_bgp_summary_information()` returns a complex XML object, what is the most effective way to access the desired data?

Accepted Answer

Use the `.find()` and `.findall()` methods with an XPath expression to directly select `bgp-peer` elements where `peer-state` is 'Established'.

Answer

Convert the XML object to a string and use regular expressions to find neighbors with the 'Established' state.

Answer

Iterate through every element in the XML object recursively and check if its text value is 'Established'.

Answer

Use the `get_bgp_neighbor_information()` RPC instead, as it returns data in a simpler format.

Question 2

What is the function of the `operation="merge"` attribute within a NETCONF ` ` RPC sent to a Junos device?

Accepted Answer

It compares the provided configuration with the target datastore and only adds or modifies elements.

Answer

It replaces the entire existing configuration with the new configuration provided in the RPC.

Answer

It deletes any configuration elements that are present in the target datastore but not in the RPC.

Answer

It creates the configuration elements only if they do not already exist in the target datastore.

Question 3

**Company Background:** Global Financial Services Inc. operates a large-scale network with strict compliance and uptime requirements. Network changes are only permitted during scheduled weekly maintenance windows and must be rigorously validated to prevent service disruptions. The network operations team is small and needs to automate as much of the change validation process as possible to reduce human error and meet tight deadlines. **Current Situation:** The team currently relies on manual CLI commands to check the state of core routers before and after applying configuration changes. This process is slow, error-prone, and generates inconsistent reports. They have decided to build an automated solution using Python, leveraging the PyEZ library for device interaction and JSNAPy for state validation. **Technical Requirements:** 1. The solution must be a single Python script that can be executed from a central automation server. 2. Before applying any changes, the script must capture a 'pre-change' snapshot of the device state. This must include the full IPv4 routing table, the status of all BGP sessions, and the operational status of all physical interfaces. 3. After changes are applied (manually or by another script), the script must capture a 'post-change' snapshot of the same data points. 4. The script must compare the two snapshots and generate a simple, clear report indicating a PASS or FAIL status. A FAIL status should be triggered if any BGP sessions have dropped, any critical interfaces have gone down, or if specific critical routes are missing from the routing table. **Constraint:** The solution must not require any custom daemons or agents to be installed on the Junos devices themselves. Which approach best satisfies all the requirements for this automated validation solution?

Accepted Answer

Create a JSNAPy configuration file that defines tests for `RouteTable`, `BGPSummary`, and `InterfaceTable`. Write a Python script that uses the `jsnapy` library to connect to the device, execute `jsnapy --snap pre`, wait for changes, execute `jsnapy --snap post`, and then run `jsnapy --check pre post` to generate the PASS/FAIL report.

Answer

Write a Python script that uses PyEZ to connect to the device, execute `show route`, `show bgp summary`, and `show interfaces terse` commands, parse the text output using regular expressions, and manually compare the pre- and post-change outputs.

Answer

Develop an Ansible playbook that uses the `juniper.junos.command` module to gather outputs and the `assert` module to validate conditions. The playbook will have separate plays for pre-check, change implementation, and post-check.

Answer

Configure on-box event scripts on each Junos device to monitor for configuration commits. The scripts will automatically capture the required operational state to a local file, which can then be retrieved and compared by a central Python script.

Question 4

An engineer is creating a YAML file to store a list of NTP servers. Which of the following snippets are syntactically correct representations of a list in YAML? (Select TWO)

Accepted Answer

ntp_servers: - 192.0.2.1 - 192.0.2.2

Accepted Answer

ntp_servers: [192.0.2.1, 192.0.2.2]

Answer

ntp_servers: (192.0.2.1, 192.0.2.2)

Answer

ntp_servers: 192.0.2.1 192.0.2.2

Answer

ntp_servers: {192.0.2.1, 192.0.2.2}

Question 5

True or False: In a mature DevOps workflow, the principle of Infrastructure as Code (IaC) encourages defining network configurations in version-controlled files, which are then used to automate deployments, ensuring consistency and repeatability.

Accepted Answer

True

Answer

False

Question 6

A PyEZ script attempts to apply a complex configuration change but fails during the commit phase, raising a `CommitError` exception. The operational requirement is that any failed commit must leave the device in its original state. How should the script's error handling be structured to meet this requirement and provide detailed logs for troubleshooting?

Accepted Answer

Wrap the `cu.commit()` call in a `try...except CommitError as e` block. In the `except` block, call `cu.rollback()` and then log the contents of the exception object `e`.

Answer

Wrap the `cu.commit()` call in a `try...except CommitError` block. In the `except` block, call `cu.load()` again with the original configuration.

Answer

Use `cu.commit(check=True)` first, and if it passes, then call `cu.commit()` inside a `try...except` block.

Answer

Before committing, save a copy of the running configuration using `dev.rpc.get_configuration()`. If `cu.commit()` fails, use `cu.load()` with the saved configuration and `overwrite=True`.

Question 7

In the context of RESTful APIs, which HTTP method is defined as idempotent and is primarily used to fully replace an existing resource or create it if it does not exist?

Accepted Answer

PUT

Answer

POST

Answer

GET

Answer

PATCH

Question 8

To execute the operational command `show chassis hardware` and receive the output as a structured XML object using PyEZ, you would use the method `dev.rpc._________()`.

Accepted Answer

get_chassis_hardware_information

Answer

get_chassis_inventory

Answer

show_chassis_hardware

Answer

command(show chassis hardware)

Question 9

An automation script needs to remove a single BGP neighbor, `198.51.100.2`, from an existing peer group named `EBGP-PEERS` without impacting any other neighbors in that group. Which `operation` attribute should be used on the ` ` element in the NETCONF ` ` RPC?

Accepted Answer

operation="delete"

Answer

operation="replace"

Answer

operation="remove"

Answer

operation="merge"

JN0-224 Sample Questions & Answers

Ready for the real thing?

JN0-224 Sample Questions & Answers

Related practice tests

Ready for the real thing?