Network engineering insights, IPAM best practices, and product updates.
A server hangs at two in the morning and the only way to see its screen is a forty-minute drive, unless a second, quieter network reaches its remote controls. What iDRAC, iLO, switch management ports, and console servers are, why their addresses belong in a block of their own, a worked carve with one subnet per device class at every site, firewall rules in plain English, and the naming and records that make it usable in the dark.
An address shows up in a conflict alert, a security report, or a cleanup list, and someone has to turn it into a box they can put a hand on. A step-by-step chain for finding the device behind an IP address: the ARP table, the MAC vendor lookup, the switch MAC table and its uplinks, the wireless controller, DHCP leases and reverse DNS as shortcuts, and the blunt methods for when every hop fails.
The office outgrew 192.168.1.0/24 and the fix is new addresses for everything. A phased playbook for renumbering on purpose: hunting down every hardcoded address, running old and new ranges side by side, the order to move things in, DNS TTL timing, and how to prove the old range is silent before you remove it.
A routing table can hold forty lines or four hundred, and the choice was made the day the addresses were handed out. How one route stands in for many subnets, the binary alignment rule that decides whether it can, where to summarize, and the two hazards (loops and hidden failures) to configure around.
The switch is named after a wizard and the person who named it quit last spring. A practical guide to hostnames, subnets, and VLANs a stranger can decode at two in the morning: the site-role-number pattern, which facts belong in a description field instead, and the turnover test every scheme should pass.
The security camera on your network is a computer that will never be patched, and by default it can reach everything you own. How to sort cameras, badge readers, and smart gadgets into trust-based VLANs, with a worked addressing plan and firewall rules in plain English.
You ask DNS who owns an address and it names a server recycled two years ago. Why forward zones, reverse PTR records, and the IP inventory drift apart, what the stale entries cost in troubleshooting and lost email, and how to make all three agree again.
Your router handed out addresses in arrival order, and now nothing is where you think it is. How to claim a private range, split static from DHCP, wall off the smart plugs with VLANs, and write down a plan that survives the next rebuild.
Every client kept their router's factory defaults, so every client network is identical. How managed service providers connect, monitor, and document fifty copies of the same subnet with NAT alias schemes, per-client VRFs, and records that treat overlap as normal.
Why a VPN that works at home dies at a hotel, how WireGuard and Tailscale hand out tunnel addresses, and why every overlay vendor settled on 100.64.0.0/10, the block reserved for carrier-grade NAT.
SNAT, DNAT, PAT, and carrier-grade NAT in plain language. How address translation actually works, the two questions that untangle the vocabulary, what NAT quietly costs, and when translation beats renumbering.
The engineer who knew the network is gone and the wiki is three years stale. How to rebuild a trustworthy IP inventory from routing tables, DHCP leases, ARP caches, DNS zones, and careful scans, without changing a single config.
A /24 by reflex wastes space on some segments and overloads others. How to size a subnet for host count, broadcast domain, blast radius, and trust boundary, before the first device joins.
Every Kubernetes cluster quietly claims a /16 for pods. How to size pod, service, and node CIDRs, avoid overlap with VPCs and VPNs, and use carrier-grade NAT space as an escape hatch.
When is a subnet at 80% a problem and when is it fine? The DHCP pool exhaustion math, growth runway forecasting, split vs re-carve decisions, and the utilization thresholds worth alerting on.
Both companies use 10.0.0.0/8 and now they have to connect. A plain-language guide to NAT at the seam, renumbering strategy, and VRFs as the mechanism that keeps both networks running during the transition.
Why two devices end up fighting over the same IP address, how to track down the culprit with the ARP table while the network is still broken, and how to make conflicts stop for good.
A plain-language decision framework for IP assignment: which devices get static addresses, what belongs in the DHCP pool, and how to carve a subnet so the two never collide.
A plain-language guide to IPv6 subnetting. Why every network gets a /64, how nibble boundaries keep plans readable, GUA vs ULA, and why sparse allocation beats conservation.
A plain-language guide to addressing point-to-point network links. When to use a /30, when to use a /31, and when to skip numbering altogether.
A long-form, plain-language tutorial that designs a complete IP address plan from scratch using a fictional mid-size company. Covers aggregation, site allocation, VLAN conventions, cloud carving, and when to use a VRF.
A plain-language reference to the 10 IP address ranges set aside for special use: private networks, carrier-grade NAT, loopback, link-local, documentation, multicast, and more.
How to track and manage IP address space across AWS, Azure, on-premises data centers, and colocation facilities from a single source of truth.
Still managing IP addresses in a spreadsheet? Here are five clear signs your team has outgrown manual IP tracking and needs a real IPAM solution.
A hands-on tutorial for automating IP address management with curl, Terraform, and Ansible using the IPCraft REST API.
A plain-language guide to how IP addresses are divided into networks, what the /24 actually means, and how to pick the right subnet size.
Spreadsheets were never designed to manage IP addresses. Here's what that workaround is actually costing your team in time, mistakes, and outages.
A plain-language guide to VLANs and VRFs, when you need each, and how they let you reuse the same IP ranges safely across different parts of your network.