Introduction: In today’s rapidly evolving network environments, automating network configuration is essential for managing complexity, ensuring consistency, and reducing human errors. Ansible, a powerful automation tool, can simplify the process of network configuration management and streamline your network operations. In this step-by-step guide, we will explore how to automate network configuration using Ansible, with a practical example to illustrate its power and simplicity.
Step 1: Setting Up Ansible Control Node
To begin automating network configuration, you’ll need an Ansible control node—a machine where Ansible is installed and runs. This can be your laptop, workstation, or a dedicated server. Ensure you have Ansible installed on this machine.
Step 2: Creating the Inventory
The inventory is a file that lists your network devices or hosts. It should include the IP addresses or hostnames of the devices you want to configure. Organize your devices into groups based on their roles, locations, or any other logical grouping.
Example inventory.yaml:
[network_devices] router.example.com switch1.example.com switch2.example.com
Step 3: Writing the Ansible Playbook
The Ansible playbook is where you define the tasks to be executed on the network devices. Each task represents a configuration change or command to be executed. Ansible uses modules to interact with network devices, simplifying the process of managing different vendors and models.
Example playbook.yaml:

In this example, we use the “ios_command” module to configure a GigabitEthernet interface on a Cisco router. The playbook sets the IP address, subnet mask, and enables the interface.
Step 4: Running the Playbook
To execute the playbook and automate the network configuration, use the “ansible-playbook” command.

Ansible will connect to the network devices listed in the inventory and execute the tasks defined in the playbook.
Conclusion: Automating network configuration with Ansible is a powerful way to improve network management and efficiency. By setting up the Ansible control node, creating an inventory of network devices, writing an Ansible playbook with specific tasks for each device, and running the playbook, you can simplify network operations and ensure consistent and reliable configurations.
Lastly, Remember that Ansible supports a wide range of network modules for various vendors and models, making it versatile and suitable for heterogeneous network environments. Adapt the example playbook to match your network devices and configurations, and explore additional Ansible network modules to enhance your automation capabilities.
Finally, Happy automating with Ansible!