350-401 Automation Practice Questions

Explanation: Netmiko is a Python library built on Paramiko that simplifies SSH automation for network devices. It can connect to multiple Cisco IOS XE devices and execute the `copy running-config tftp:` command with robust prompt handling and minimal custom code, making it well suited for scripted backups. Ansible is an external automation framework, RESTCONF is an API interface, and Paramiko requires lower-level SSH handling and more custom code for the same task.

Explanation: The 201 Created status indicates that the server accepted the request, but the loopback interface was not actually created because the PUT method is not appropriate for creating a new list resource in the Cisco IOS XE RESTCONF implementation. According to the RESTCONF protocol, POST is used to create a new data resource when the client does not provide the exact resource identifier, while PUT is used to replace or create a resource when the client specifies the entire URI. However, for list entries in YANG data models, some implementations (including Cisco IOS XE) require POST to the list node to create a new instance, as PUT to a specific instance may only be effective if the instance already exists or may be accepted but not committed to the running configuration. Therefore, even though a 201 was returned, the configuration was not applied, indicating that a POST request to /restconf/data/Cisco-IOS-XE-native:native/interface/Loopback would have been the correct approach.

Explanation: The ios_config module requires the connection parameter to be set to 'network_cli' (or 'ansible.netcommon.network_cli') to use the CLI transport for sending configuration commands to network devices. Without this, Ansible defaults to the 'smart' connection, which may not properly interact with network device CLIs, causing the playbook to run without errors but not apply the ACLs.

Explanation: NETCONF/YANG (A) is a valid automation method on Cisco IOS XE because IOS XE supports NETCONF over SSH (port 830) with YANG data models, allowing programmatic configuration via <edit-config> operations. CLI via SSH with Python, such as Netmiko (D), is valid because Netmiko establishes an SSH session and sends IOS/IOS XE CLI commands, which is a widely used automation approach even though it is screen-scraping rather than model-driven. RESTCONF (E) is valid because IOS XE exposes RESTCONF over HTTPS (port 443) with YANG-modeled resources, enabling configuration through HTTP methods like POST, PUT, PATCH, and DELETE. SNMP Set requests (B) are not a valid configuration-automation method here, since SNMP is primarily used for monitoring and its Set operations are limited and not a supported model-driven configuration interface on IOS XE. Telnet with Expect scripts (C) is not valid because Telnet is an insecure, legacy protocol and Expect-based CLI scripting is not a supported or recommended IOS XE automation method.

Explanation: The ios_config module in Ansible, by default, uses a 'set' operation that appends commands to the running configuration. To change an existing IP address on an interface, the module must be configured with the 'replace' option or use a 'before'/'parents' directive to remove the old address first. Without this, the new IP command is added but the old one remains, and the interface retains the original address because Cisco IOS allows multiple IP addresses on a single interface only if the secondary keyword is used, which the module does not automatically apply.