Network Automation with Ansible: A Practical Guide

Introduction

Ansible enables repeatable, version-controlled network automation across major vendors.

Setup

bash

1python -m venv .venv
2source .venv/bin/activate
3pip install ansible ansible-pylibssh
4ansible-galaxy collection install cisco.ios

Inventory

yaml

1# inventory.yml
2all:
3  children:
4    routers:
5      hosts:
6        core-rtr-01:
7          ansible_host: 192.168.1.1
8          ansible_network_os: cisco.ios.ios
9      vars:
10        ansible_connection: ansible.netcommon.network_cli
11        ansible_user: admin
12        ansible_ssh_private_key_file: ~/.ssh/network_key

First Playbook

yaml

1- name: Gather Network Facts
2  hosts: routers
3  gather_facts: no
4  tasks:
5    - name: Gather IOS facts
6      cisco.ios.ios_facts:
7        gather_subset:
8          - all

Roles and Variables

Split configs into roles
Use group_vars/host_vars
Keep secrets in Ansible Vault

Run

bash

1ansible-playbook -i inventory.yml gather_facts.yml

Conclusion

Ansible turns manual CLI changes into auditable automation.

Ansible

Cisco IOS

YAML

Python

Written by

Corentin Tujague

Network & Security Engineer

Passionate about building secure, scalable infrastructure and sharing technical knowledge.