Pets vs Cattle

From Pets to Cattle: Changing How We Think About Networks and Servers

When you first get into IT, it’s natural to treat every server and network device like a pet. You name them, you care for them, you spend time fixing them when they get sick. You might even have some favorites you secretly root for. It’s kind of like having a dog. You don’t just replace a dog when it gets sick. You do whatever you can to heal it.

For a long time, this was just how things were done. Servers were built by hand. Network devices were configured line-by-line on the CLI. If something broke, you had to fix it. Rebuilding wasn’t easy, and automation was either too expensive or just out of reach for most teams.

But as environments grew bigger and more complex, this “pets” mentality stopped making sense. You can’t individually care for hundreds or thousands of servers and switches like that. That’s when the idea of treating infrastructure like cattle started to catch on.

Instead of hand-raising every machine, you design systems to be easily replaceable. If a server or device has a problem, you don’t spend hours nursing it back to health. You spin up a new one and move on. The goal shifts from saving the individual machine to keeping the overall environment healthy.

Why This Shift Matters

The old way of treating infrastructure like pets made sense when you only had a few systems. But as technology has grown, so has the need for speed, consistency, and scale.
Modern environments demand a different approach — one where resilience and automation are built into everything from day one.

Rather than being the firefighter who knows every server inside and out, the goal now is to design systems that don’t catch fire in the first place.

Automation is What Makes This Possible

Rather than manually configuring every system, we define how things should look and let automation take care of the rest.

Networking Automation

On the network side, one of the ways to start moving toward this model is by using NetBox as your design source of truth.
Instead of keeping designs in spreadsheets or tribal knowledge, you document everything centrally.
Then, with tools like Ansible, you can automatically generate and deploy network configurations.

Need to bring up a new switch or firewall? Pull the details from NetBox, push the config with Ansible, and you are ready to go.

Networking Automation Flow

Design: Document network topology and device roles in NetBox

Source of Truth: NetBox holds IPs, VLANs, devices, and relationships

Automation Engine: Use Ansible to pull info from NetBox

Deployment: Push configurations to switches, routers, and firewalls

Verification: Optionally run tests post-deployment (ping tests, config checks)

Server Automation

On the server side, tools like Terraform and Docker come into play.

Terraform lets you define infrastructure as code, from virtual machines to storage and networking.
Docker handles packaging and running applications in clean, portable containers.

If a server goes down, you do not panic. You redeploy with Terraform and spin your containers back up just like before.

Server Automation Flow

Infrastructure as Code: Define servers, networks, and storage with Terraform

Provisioning: Terraform builds VMs, cloud resources, or even bare metal

Application Layer: Package apps into containers with Docker

Deployment: Deploy containers to new or rebuilt infrastructure

Scaling and Recovery: Redeploy or scale automatically by updating definitions

Final Thoughts

Switching from a pets mindset to a cattle mindset is not about caring less — it’s about designing better from the beginning.
It’s about building environments that are resilient, consistent, and easy to grow.

Automation is what enables this shift.
By treating your infrastructure as something that can be rebuilt at any time, you gain freedom.
Freedom to scale, freedom to recover quickly, and freedom to focus your energy on building rather than constantly firefighting.

It might feel strange at first, but once you embrace this new way of thinking, it becomes hard to imagine doing it any other way.