# Network Automation: From CLI to Infrastructure as Code
Network engineers learned their craft at the command line. Telnet sessions. SSH terminals. Typing commands. Watching output. Copying configurations. This hands-on approach built deep understanding. It scales poorly.
Modern networks contain thousands of devices. Manual configuration creates backlogs. Human error causes outages. Configuration drift accumulates. The craft approach that built expertise now limits what networks can become.
Network automation applies software engineering practices to network operations. Configuration becomes code. Version control tracks changes. Automation deploys consistently. The journey from CLI to Infrastructure as Code transforms how networks operate.
## The Automation Journey
Most organisations progress through stages.
**Scripts** provide initial automation. Python scripts SSH to devices and execute commands. Faster than manual typing. Still fragile and device-specific. Better than nothing, but just the beginning.
**Configuration management** brings structure. Ansible, Salt, or Puppet manage device configurations. Templates generate consistent output. Inventory tracks devices. Idempotent execution enables safe re-runs.
**Infrastructure as Code** declares intent. Terraform for cloud network resources. Network-specific tools for physical infrastructure. Desired state declared, automation achieves it. True infrastructure as code.
**GitOps** adds workflow rigour. Configuration lives in Git. Changes require pull requests. Review before merge. CI/CD pipelines deploy approved changes. Complete audit trail.
## Key Practices
Successful network automation requires adopting new practices.
**Source of truth** must be established. Where does authoritative configuration live? IPAM for addressing. CMDB for inventory. Data must be accurate and current. Automation amplifies errors in source data.
**Testing** validates changes safely. Lab environments mirror production. Automated tests verify configuration. Staged rollouts limit impact. Never deploy untested changes to production.
**Modularity** enables reuse. Standard templates for standard configurations. Variables customise for specific instances. Roles and modules encapsulate common patterns.
**Version control** provides history and collaboration. Git tracks all configuration. Branching enables parallel development. Merge requests facilitate review.
## Overcoming Obstacles
Automation adoption faces common challenges.
**Skill gaps** require investment. Network engineers need programming basics. Software concepts like version control must be learned. Training and practice build capability.
**Legacy devices** may lack automation support. Older equipment supports only CLI. Screen scraping provides fallback. Plan for modernisation.
**Cultural resistance** slows adoption. Change is uncomfortable. Start with willing early adopters. Demonstrate value. Expand gradually.
If your organisation needs help implementing network automation or training your team in modern practices, contact us through our contact page.