Automated Test for Validating Interface Functionality

B.

The correct answer to this question is D - "Add a pipeline step that captures and parses the show ip interface output so that the operational state can be referenced."

When making configuration changes to network devices, it's important to validate that the changes have been successfully applied and that the device is functioning as expected. In this case, an Ansible playbook was used to push the configuration change to the device, specifically using the ios_config module.

Option B suggests that automated testing is already built-in because the playbook execution is successful only after Ansible validates that it applied the change. However, this only ensures that the configuration change was applied successfully; it doesn't validate whether the interface is functioning as it should.

Option A suggests running the playbook a second time and checking if it modifies the device. While this may work in some cases, it's not a reliable method for validating that the interface is functioning correctly.

Option C suggests capturing and parsing the packet flow for the interface. While this would provide useful information about the traffic flowing through the interface, it doesn't directly validate that the interface is functioning as it should.

Option D, on the other hand, suggests capturing and parsing the "show ip interface" output, which provides detailed information about the current operational state of the interface. This output includes information about the interface's IP address, status, protocol, and various other metrics that can be used to validate whether the interface is functioning correctly. By adding a pipeline step to capture and parse this output, it's possible to validate that the interface is configured and functioning as expected.

In summary, the correct answer is D because it provides a direct method for validating the operational state of the interface after the configuration change has been applied using Ansible.