Long-form articles on subnetting, VLSM, cloud network design, and Kubernetes networking. Written for working engineers — no fluff, with examples you can copy.
The articles below cover the topics that come up over and over in real network and cloud engineering: how cloud providers reserve IP addresses inside your VPC subnets, how variable-length subnet masking lets you allocate address space efficiently, the binary mechanics behind subnet math, what changes when you move from IPv4 to IPv6, how to plan pod and service CIDRs for Kubernetes clusters that scale, and when to reach for a subnet calculator versus an IP calculator. Each article is written for working engineers — concise, with worked examples and concrete recommendations rather than encyclopedic overviews.
Most posts also link out to our subnet calculator, VLSM planner, and the cloud-aware subnet tool, so you can verify the math from the article against a live calculation. Everything on this site runs in your browser; the calculators never send your network designs to a server.
AWS reserves 5 IP addresses in every VPC subnet. This article explains which addresses get reserved, why the minimum subnet size is /28, and how to plan VPC capacity for production growth without running out of address space.
Take a /22 parent block and allocate five subnets for engineering, sales, ops, DMZ, and management. A step-by-step walkthrough of boundary alignment, largest-first allocation, and how to avoid the fragmentation traps that bite naive VLSM designs.
Subnet math from first principles: binary masks, AND/OR operations to find network and broadcast addresses, how to count host bits, and CIDR notation. Worked examples for the most common prefix sizes: /24, /28, and /30.
IPv6 for engineers used to IPv4. Covers 128-bit addressing, /64 as the standard subnet size for SLAAC compatibility, link-local versus global unicast, multicast addressing, and the practical differences you will hit migrating from IPv4.
Plan pod and service CIDRs for Kubernetes clusters that scale. Avoid the common VPC-overlap trap, size pod-network CIDRs for node counts you actually plan to run, and integrate with AWS VPC CNI or GCP alias IP ranges correctly.
When you need CIDR math (host counts, network and broadcast, mask conversion) versus IP lookup (geolocation, validation, reverse DNS). Comparison with concrete examples and the engineering decisions each tool helps with.
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