1.8 Summarize evolving use cases for modern network environments
Infrastructure as Code (IaC)
📘CompTIA Network+ (N10-009)
nfrastructure as Code (IaC) is a modern way of deploying and managing IT infrastructure using code instead of manual configuration.
Instead of clicking buttons on a GUI or logging into each device manually, administrators write scripts or configuration files that define:
- What devices should exist
- How they should be configured
- What updates they should receive
- How the network should behave
The goal of IaC is consistency, speed, and automation.
In the Network+ exam, you must understand how IaC supports automation using several important components:
- Playbooks
- Templates
- Configuration Drift
- Upgrades
- Dynamic Inventories
Let’s break each down in simple English.
1. Playbooks
What are Playbooks?
A playbook is a file that contains a set of instructions or tasks that automation tools follow.
It tells the system:
- What to configure
- When to configure it
- How to apply the configuration
Think of a playbook as a step-by-step recipe written in code for setting up or modifying network devices.
Why Playbooks Matter in IaC
- They automate repetitive tasks
- They ensure consistent configuration across all devices
- They allow you to run the same steps again and again without mistakes
- They can be stored in version control systems (like Git) for tracking changes
What the Exam Wants You to Know
- Playbooks are part of automation tools used in IaC
- They contain the tasks and workflows to configure network infrastructure
- They help ensure repeatable and error-free deployments
2. Templates
What Are Templates?
A template is a file that defines a general configuration structure but allows certain values to be filled in dynamically.
Templates ensure that many devices can use the same configuration format, with only the necessary differences changed automatically.
For example, a template might contain:
- Interface names
- IP addresses
- Hostnames
- Routing settings
…but will fill each value from variables instead of manually editing each device’s config.
Why Templates Matter
- Reduce manual editing
- Ensure consistency
- Make large deployments faster
- Allow administrators to generate many device configs from one source file
Exam Focus
- Templates provide standardized yet flexible configuration
- They use variables to customize settings for each device
- They help avoid errors caused by manual typing
3. Configuration Drift
What Is Configuration Drift?
Configuration drift happens when the actual device configuration no longer matches the intended configuration defined in code.
This can occur when:
- Someone makes manual changes on a device
- A patch updates or alters configuration
- A device fails, reboots, or syncs incorrectly
- Multiple administrators apply inconsistent settings
Over time, devices that were once identical can become misaligned.
Why Configuration Drift Is a Problem
- Causes inconsistencies
- Makes troubleshooting difficult
- Leads to outages or security vulnerabilities
- Breaks automation workflows
- Can cause network devices to behave unpredictably
How IaC Fixes Configuration Drift
IaC tools can:
- Detect drift
- Alert administrators
- Automatically correct the configuration
- Reapply the intended state
Exam Concepts
- Drift = unintentional configuration changes
- IaC helps detect and remediate drift
- Maintaining a “desired state” is a key IaC function
4. Upgrades
What Are Upgrades in IaC?
Upgrades refer to automated updates applied to:
- Operating systems (OS) on network devices
- Firmware
- Software packages
- Security patches
- Configuration versions
IaC allows upgrades to be pushed using automated scripts or workflows rather than manually.
Benefits of Automated Upgrades
- Reduces downtime
- Ensures consistency across devices
- Avoids human error
- Makes large-scale updates easier
- Ensures devices stay secure and compliant
Example Tasks in an Automated Upgrade Process
An IaC upgrade workflow may:
- Back up existing configuration
- Push the new firmware
- Apply configuration updates
- Validate the device after reboot
- Log success or failures
Exam Focus
- Upgrades can be automated through IaC
- Automation ensures uniform, repeatable, and safe updates
- Helps remove unreliable manual upgrade processes
5. Dynamic Inventories
What Are Dynamic Inventories?
A dynamic inventory automatically discovers and lists:
- Devices
- IP addresses
- Hosts
- Cloud resources
Instead of building an inventory file manually, IaC tools query:
- Cloud platforms
- Virtual environments
- Network discovery tools
- Orchestration systems
The inventory updates itself whenever devices:
- Are added
- Are removed
- Change IP
- Move between environments
Why Dynamic Inventories Matter
- Greatly reduces manual administrative work
- Ensures that automation always targets the correct devices
- Prevents errors caused by outdated device lists
- Helps in large or frequently changing environments (e.g., cloud networks)
Static vs Dynamic Inventory
| Static Inventory | Dynamic Inventory |
|---|---|
| Manually maintained file | Automatically generated |
| Good for small, unchanging networks | Best for cloud and large networks |
| Prone to outdated entries | Always up to date |
Exam Key Points
- Dynamic inventories update automatically
- Used when environments scale quickly
- Essential for cloud and virtualized infrastructure automation
Summary Table (Exam-Friendly)
| IaC Term | Meaning | Why It Matters |
|---|---|---|
| Playbooks | Files containing tasks and automation instructions | Ensures repeatable, error-free deployments |
| Templates | Standardized configuration files with variables | Deploys many device configs consistently |
| Configuration Drift | When device config differs from intended state | IaC detects and fixes drift to maintain consistency |
| Upgrades | Automated firmware and software updates | Safe, consistent, and efficient updating |
| Dynamic Inventories | Auto-discovered list of devices for automation | Always accurate, reduces manual work |
Final Notes for Students
For the Network+ (N10-009) exam:
- Understand what each term means
- Know how these IaC components help automation
- Remember how IaC improves consistency, speed, and reliability
- Focus on the goal: reducing manual work and mistakes in modern network environments
