1. Python
It's impossible to discuss network automation without starting with Python. It has become the de facto standard for interacting with network devices programmatically, and for good reason. Its clean syntax, extensive libraries, and massive community make
it incredibly accessible for network engineers who are new to coding. Cisco has fully embraced Python, making it a cornerstone of its DevNet program and a recommended skill for its certifications. Libraries like Netmiko and Paramiko allow you to SSH into devices to pull data or push configurations, effectively turning repetitive manual tasks into simple, reusable scripts. Furthermore, Python is essential for interacting with the APIs of major Cisco platforms like DNA Center, Meraki, and ACI.
2. Ansible (with YAML)
While Python lets you build custom scripts from scratch, Ansible provides a powerful framework for automation. It uses a human-readable language called YAML to define "playbooks" that describe the desired state of your network. Ansible is agentless, meaning it communicates with Cisco devices over standard protocols like SSH, without requiring special software to be installed on the switches or routers. This makes it incredibly popular for configuration management. Cisco provides a vast number of Ansible modules specifically for its products, from IOS XE to Catalyst Center, allowing you to manage everything from VLANs and interfaces to complex security policies with simple, declarative playbooks. This simplifies large-scale changes and ensures consistency across your infrastructure.
3. Go (Golang)
If Python is the versatile multitool of network automation, Go is the high-performance specialist. Developed by Google, Go is a compiled language known for its speed and efficiency, especially in concurrent operations—that is, doing many things at once. In a networking context, this makes it ideal for building high-performance services, custom exporters that scrape metrics from thousands of devices, or command-line tools that need to execute instantly. While its library ecosystem for networking isn't as vast as Python's, it is growing steadily. For engineers looking to build robust, production-grade network applications that can handle massive scale, learning Go provides a significant performance advantage over interpreted languages like Python.
4. YANG
YANG isn't a traditional programming language, but a data modeling language that is critical to modern network management. Standing for "Yet Another Next Generation," YANG provides a standardized, predictable way to describe the capabilities and configuration of a network device. Think of it as a contract or a blueprint for a device's API. When you interact with a modern Cisco device using a protocol like NETCONF, the data is structured according to a YANG model. Understanding how to read YANG models allows you to discover exactly what you can configure and monitor on a device without guesswork. It's the foundational layer that enables reliable, cross-vendor automation by ensuring that both the engineer and the device are speaking the same structured language.
5. Terraform (HCL)
Terraform, and its underlying HashiCorp Configuration Language (HCL), has become the standard for Infrastructure as Code (IaC). While Ansible is often used to configure existing devices, Terraform excels at provisioning and managing the lifecycle of the infrastructure itself. Cisco has invested heavily in creating Terraform providers for its key platforms, including ACI, DNA Center, Meraki, and even security products like Secure Firewall. This allows you to define your entire network architecture—from data center fabrics to branch office SD-WAN—in code. You can then create, update, and destroy environments in a repeatable and version-controlled manner, extending the principles of DevOps to networking.
6. JavaScript
While most network automation happens on the backend, many Cisco platforms expose rich graphical user interfaces and APIs that are built on web technologies. The Cisco APIC GUI, for example, is a JavaScript application. Knowing JavaScript is essential if you want to build custom dashboards, create front-end tools that consume Cisco APIs, or customize user experiences within platforms like Cisco Finesse for contact centers. With the rise of web-based management interfaces for nearly all network products, having a grasp of JavaScript allows you to go beyond the command line and build truly integrated, user-friendly solutions on top of the Cisco stack.
