Networking Practical By Samson Tanimawo, PhD Published Jun 17, 2025 4 min read

IP Allocation Discipline

IPAM.

Use an IPAM tool

AWS IPAM, NetBox, or similar. Single source of truth for IP allocations.

Avoids collisions across teams and accounts.

Surfaces conflicts before they happen.

10/8 reserved for VPCs. Per-region /12 blocks. Per-VPC /16 default.

Smaller blocks for smaller VPCs. Don't over-allocate.

Reserved space for growth. Allocate at half capacity initially.

Unused allocations: reclaim. Free up address space.

Over-allocated VPCs: candidates for downsizing.

Approaching capacity: plan expansion.

IaC integration. Terraform module pulls allocation from IPAM.

Auto-allocation for new VPCs. Engineers don't pick CIDRs manually.

Audit log: every allocation traceable to a request.