Getting Started

Welcome to Subnetter! This section will help you get up and running quickly.

What is Subnetter?

Subnetter is a tool for hierarchical IPv4 CIDR allocation across cloud infrastructure. It automates IP address planning for multi-account, multi-region, multi-cloud deployments.

Key Benefits

Deterministic

Same configuration always produces the same allocations. Perfect for reproducible infrastructure.

Zero Conflicts

Mathematically guaranteed non-overlapping CIDRs. No more debugging IP conflicts.

Multi-Cloud

Native support for AWS, Azure, and GCP with provider-specific naming conventions.

Scalable

Plan for growth from day one. Add accounts, regions, and subnets without re-IP projects.

Quick Links

Quick Start Get your first allocation in under 5 minutes

CLI Reference Complete command-line documentation

Configuration Reference All configuration options explained

CIDR Primer Learn CIDR notation fundamentals

How It Works

Subnetter divides your IP space hierarchically:

Base CIDR (10.0.0.0/8)
├── Account 1 (/16)
│   ├── Region 1 (/20)
│   │   ├── AZ 1 (/22)
│   │   │   ├── Public (/24)
│   │   │   ├── Private (/24)
│   │   │   └── Data (/26)
│   │   └── AZ 2 (/22)
│   └── Region 2 (/20)
└── Account 2 (/16)

Each level gets a dedicated, non-overlapping slice of IP space.

Workflow

1. Define your cloud structure in a JSON or YAML config file
2. Generate allocations with subnetter generate
3. Integrate the CSV output with Terraform, CloudFormation, or other IaC tools
4. Version control your config for auditable, reproducible infrastructure

Supported Cloud Providers

Provider	Region Format	AZ Format
AWS	us-east-1	us-east-1a
Azure	eastus	eastus-1
GCP	us-central1	us-central1-a

Next Steps

Ready to get started? Head to the Quick Start guide.

Or explore:

• Best Practices - CIDR allocation strategies
• Real-World Examples - Complete configurations for common scenarios
• Troubleshooting - Common issues and solutions