Configuration Management Tools

Configuration management tools automate the deployment and maintenance of consistent configurations across network devices. The CCNA v1.1 specifically tests Ansible and Terraform.

Ansible

Ansible is an open-source automation tool that is particularly popular for network device configuration.

Key Characteristics

Ansible Components

Example Ansible Playbook (Network)

---
- name: Configure VLANs on switches
  hosts: access_switches
  gather_facts: no
  tasks:
    - name: Create VLAN 10
      cisco.ios.ios_vlans:
        config:
          - vlan_id: 10
            name: SALES
            state: active
        state: merged

    - name: Configure access port
      cisco.ios.ios_config:
        lines:
          - switchport mode access
          - switchport access vlan 10
        parents: interface GigabitEthernet0/1

Terraform

Terraform is an infrastructure-as-code tool for provisioning and managing infrastructure resources.

Key Characteristics

Terraform Workflow

1. Write — Define infrastructure in .tf files (HCL language)
2. Plan — Preview what changes will be made (terraform plan)
3. Apply — Execute the changes (terraform apply)
4. Destroy — Remove all managed resources (terraform destroy)

Example Terraform Configuration

resource "aws_vpc" "main" {
  cidr_block = "10.0.0.0/16"

  tags = {
    Name = "Production-VPC"
  }
}

resource "aws_subnet" "web" {
  vpc_id     = aws_vpc.main.id
  cidr_block = "10.0.1.0/24"

  tags = {
    Name = "Web-Subnet"
  }
}

Ansible vs. Terraform

When to Use Each

Other Configuration Management Tools

On the Exam: Know that Ansible is agentless (uses SSH), uses YAML playbooks, and is ideal for network device configuration. Terraform is declarative, uses state files, and is primarily for infrastructure provisioning. Both support idempotency.