Network Automation and Programmability

Learning objectives

• Explain the purpose and scope of Network Automation and Programmability.
• Identify important protocols, roles, fields, and terminology.
• Apply the concept to a practical network scenario.
• Use IOS XE commands to verify operational behavior.

1. Core concepts

Traditional networking often configures devices individually through CLI. Controller-based networking centralizes intent, policy, topology, or automation workflows. The control plane makes forwarding decisions; the data plane forwards packets using installed state; the management plane configures and monitors devices.

2. How it works

REST APIs commonly use HTTP methods: GET reads, POST creates or invokes, PUT replaces, PATCH partially modifies, DELETE removes. JSON represents structured objects and arrays. Northbound APIs expose controller capabilities to applications; southbound interfaces connect controllers to devices. YANG models configuration and operational data.

Visual walkthrough

3. Worked example

A controller API might use GET /api/v1/devices to retrieve a device list. A PATCH request may update a resource using JSON. Idempotent automation can be repeated safely to converge on the same desired state. Protect credentials, validate changes, use version control, and plan rollback.

IOS XE commands and verification

Syntax and feature availability can vary by device family and software release. Confirm platform support before applying configuration.

Illustrative REST request, not IOS XE CLI
GET https://controller.example/api/v1/devices
Accept: application/json
Example JSON hostname edge-01 ntp_enabled true
show version
show running-config section restconf

Common mistakes and troubleshooting

• Check physical and interface state before changing higher-layer settings.
• Verify both ends agree on addressing, VLAN, encapsulation, and protocol parameters.
• Use operational show commands; configured text alone does not prove a feature is working.
• Change one variable at a time and verify the result.

Knowledge check

Choose one answer per question. Submit to see why the correct choice is right and why every other option is wrong. These are original practice questions, not Cisco exam questions.