Blog
Network engineering insights, IPAM best practices, and product updates.
Anycast Explained: How One IP Address Can Live in Hundreds of Places at Once
A ping to 1.1.1.1 comes back in 9 milliseconds in Chicago and 11 in Sydney, faster than light could travel between the two. How anycast lets hundreds of servers share one IP address: how internet routing sends each visitor to the nearest copy, why nearest by network can differ from nearest on a map, why DNS root servers, public resolvers, and CDNs depend on it for speed, failover, and attack resistance, how to spot an anycast address yourself, and how to use and document it inside your own network.
How to Read a Traceroute: Stars, Latency Jumps, Asymmetric Paths, and MPLS Hops
Hop 6 took 244 milliseconds, two rows timed out, and a router in New York answered in London's time, and none of it was the problem. How to read traceroute output in plain language: what each line and number means, why stars and a single slow hop are usually harmless, how distance, return paths, and load balancing shape the times, how MPLS tunnels hide hops or flatten their times, and how to find the hop where a real problem starts.
A Repeatable Addressing Template for Branch Offices, from 5 Sites to 500: One Block per Site, One Layout Everywhere
Every new site built by hand becomes one more layout to learn and one more place for a mistake to hide. How to give every branch office a block of addresses the same size, divided the same way: sizing the block for the largest ordinary site, a top-level carve with room for a thousand locations, a sixteen-slot template with fixed offsets and VLAN numbers, a site-number formula, and the exceptions, IPv6 version, and records that keep it working from five sites to five hundred.
Why a Ping Sweep Misses Half Your Network: Silent Firewalls, Sleeping Laptops, and What ARP, nmap, and DHCP Leases Can't See
The new printer got an address that never answered ping, and by lunch it was fighting a computer that had held that address for three years. Why a ping sweep finds fewer than half the devices on a typical office network: Windows firewalls that ignore ping, sleeping laptops and phones, what the ARP table, nmap, and DHCP leases each see instead, what no method can see, and how to combine them into a count you can trust.
Why the Guest Wi-Fi Dies Before the Keynote: Sizing Wi-Fi and Guest Subnets for Devices You Don't Control
Every radio is up and the network still stops working at twenty past nine, because a /22 that sounded generous ran out of addresses. How to size wireless subnets by counting devices instead of people, why lease time is capacity, the hour-by-hour arithmetic of a conference, one subnet per SSID, roaming and randomized addresses, and a redrawn worked plan with the records that keep it honest.
The Network You Use When the Network Is Down: Designing Out-of-Band Management for iDRAC, iLO, Switches, and Console Servers
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.
Who Has 10.0.4.17? Tracing an IP Address Back to a Physical Device
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.
Renumbering a Network Without Downtime: A Phased Migration Playbook
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.
Supernetting and Route Summarization: Designing Address Blocks That Keep Routing Tables Small
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.
Naming Things Is Hard: Conventions for Subnets, VLANs, and Hostnames That Survive Employee Turnover
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.
Segmenting IoT and OT Devices: An Addressing Plan for Cameras, Badge Readers, and Everything You Don't Trust
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.
Your IP Inventory and Your DNS Zones Disagree: Keeping Forward, Reverse, and Reality in Sync
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.
Home Lab IP Addressing Done Right: A Sensible Plan for Your Growing Network
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.
IP Planning for MSPs: Managing Fifty Clients Who All Use 192.168.1.0/24
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.
VPN and Overlay Network Addressing: WireGuard, Tailscale, and the Ranges That Don't Collide
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.
NAT Explained: SNAT, DNAT, PAT, and When Translation Is the Right Answer
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.
You Inherited a Network Nobody Documented: Building an IP Inventory from Scratch
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.
How Big Should a Subnet Actually Be? Right-Sizing Broadcast Domains
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.
IP Planning for Kubernetes: Pod CIDRs, Service CIDRs, and the Day You Run Out of 10/8
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.
How Full Is Too Full? Subnet Utilization and IP Capacity Planning
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.
Merging Two Networks After an Acquisition: A Survival Guide for Overlapping Subnets
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.
IP Address Conflicts: How They Happen, How to Find Them, How to Prevent Them Forever
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.
DHCP, Static, or Reservation? Deciding How Every Device Gets Its Address
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.
IPv6 Address Planning: Why Everything You Know About Conserving Space Is Wrong
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.
Point-to-Point Links: /30 vs /31 vs Unnumbered
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.
Designing an IP Plan from Scratch: A Worked Example
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.
The 10 Reserved IP Ranges Every Network Engineer Should Know
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.
IP Address Management for Multi-Cloud and Hybrid Networks
How to track and manage IP address space across AWS, Azure, on-premises data centers, and colocation facilities from a single source of truth.
5 Signs You've Outgrown Manual IP Tracking
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.
Automating IP Allocation with the IPCraft API
A hands-on tutorial for automating IP address management with curl, Terraform, and Ansible using the IPCraft REST API.
Subnetting Made Simple: A Visual Guide to CIDR Notation
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.
Why Your Team Is Still Using a Spreadsheet for IP Management (And What It's Costing You)
Spreadsheets were never designed to manage IP addresses. Here's what that workaround is actually costing your team in time, mistakes, and outages.
VLANs vs VRFs: When You Need Overlapping Address Space
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.