The Project That Triggered This Post
Recently, I was assigned to a mid-scale network migration spanning three data centers.
The architecture was straightforward but labor-intensive: dozens of VRFs, hundreds of point-to-point BGP sessions in a BGP fabric, and a VMware NSX overlay. Despite this modern setup, I was asked to manually write all of the configuration changes as CLI.
After coding over 6,000 lines of CLI that night, I paused to reflect:
- Should network design in 2025 still rely on manual CLI output?
- Are we truly addressing the core architecture, or merely throwing syntax at complexity?
A better question would have been:
Could we design this multi-site data center fabric in a more automated, intent-driven way from the start?
The Real Problem: We’re Designing Backwards
The network itself wasn’t broken — but the approach was.
In this case, the team had been:
- Manually subnetting point-to-point IP addresses in spreadsheets or Notepad
- Copy-pasting BGP neighbor configurations with only ASNs changed
- Dispersing route-redistribution logic across individual devices
- Adding a VMware NSX overlay as an abstraction layer that didn’t reduce complexity
The design lacked any intent-based modeling.
The CLI became both the glue holding the solution together and the scapegoat for its shortcomings.
Manual IP Subnetting is Outdated
Today, manually calculating point-to-point subnets shouldn’t exist.
Instead:
- Define IP pools
- Define automated assignment policies
- Let software handle the math
In an API-first, cloud-first, IaC world, we shouldn’t still be solving BGP mesh addressing with “spreadsheet math.”
It’s slow, brittle, and architecturally obsolete.
The Role We Should Play
As network architects, our job is not to churn out config lines.
We are hired to:
- Validate and verify design logic
- Model configuration intent
- Align topology with business and security requirements
- Build networks that are scalable, observable, and automatable
In other words:
Stop being a config writer. Start being a design validator.
We demonstrate value through architecture, not typing speed.
What Needs to Change
Technically:
- Use centralized IP pools and templates
- Automate config generation (Python, Jinja2)
- Use structured intent (YAML/JSON)
- Leverage design metadata to generate configs
- Adopt modern fabrics (ACI, EVPN-VXLAN) to simplify multi-site design
Culturally:
- Stop accepting “just give me the config”
- Steer the conversation toward design validation
- Respond with partnership such as:
“Let me review the design logic first and deliver a reusable configuration model.”
This reframes you as a strategic advisor — not a syntax producer.
If You’re Still Writing CLI Manually…
Here’s the hard truth:
If you’re typing every line by hand, you’re proving you can type, not that you can think.
Don’t let decades of experience be reduced to syntax.
Your value is in strategy, not the keyboard.
Conclusion: Be the Strategic Advisor, Not the Keyboard Resource
We often hear:
“Hey, can you just generate the config for us?”
A better response:
- “Yes — but let me first review the design so I’m not just fixing symptoms.”
- “Let’s align on the architecture model so we don’t create another one-off solution.”
Because the future of network design isn’t more CLI.
It’s:
- better context
- better consistency
- smarter delivery