How to Automate Configuration of Cisco Devices Using Ansible (Step-by-Step Guide)

Introduction

In large organizations with many Cisco devices, managing each device manually is time-consuming and complex. Ansible enables centralized and automated configuration across multiple devices simultaneously, saving time, reducing costs, and improving network security and efficiency. This approach allows organizations to respond quickly to network changes and requirements, maximizing resource utilization.

Using Ansible automation not only accelerates the configuration process but also minimizes human errors caused by manual settings. In this guide, we demonstrate how to use Ansible for configuring Cisco devices, including enabling or disabling SNMP version 3.

Prerequisites

• A Linux-based OS (all examples here use Ubuntu 22)
• Installed Ansible
• Required Ansible modules
• One or more Cisco devices
• SSH access with privilege level to configure the device

Limitations

• Ensure the Cisco IOS version is 15 or higher. If using version 12, you may encounter limitations with modules like ios_vlans, ios_interfaces, ios_facts, etc.
• SSH must be enabled on the device for Ansible to communicate with it.
• Tip: If testing SSH manually, use OpenSSH v7 on Linux. Newer versions may not support older Cisco protocols. As a workaround, use Ubuntu 18 or older in Docker temporarily.

Step-by-Step Guide

Step 1: Install Ansible and Cisco IOS Module

sudo apt-get update
sudo apt-get install ansible -y 

Then, install the Cisco IOS collection:

ansible-galaxy collection install cisco.ios

Note: You may encounter 403 errors when installing modules from Iran. In such cases, use a VPN or proxy with a non-Iranian IP address.

If successful, you’ll see output confirming module installation (see screenshots in the original guide).

Step 2: Install Python-Based Tools for Cisco Communication

Install pip, the Python package manager:

apt install python3-pip

Then install the following Python packages:

pip install pyyaml

pip install paramiko

pip install netmiko

Ensure that each package ends with a “successfully installed” message.

Step 3: Configure the Inventory and Playbook Files

Inventory File (inventory.ini)

This file defines which devices Ansible will configure, including host IPs, credentials, and connection methods.

Playbook File (snmpv3_config.yml)

This file contains the actual commands and configurations to apply:

Final Step: Run the Playbook

Use the following command to run the playbook:

ansible-playbook -i inventory.ini snmpv3_config.yml

This setup provides a scalable and efficient method to automate Cisco device management with Ansible, improving consistency, reliability, and response time in enterprise networks.