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Tools for engineersby engineers
The utilities we reach for on the job, built properly and put here free for anyone who needs the same. Some take something you already have — a config, a SMART dump, a traceroute — and tell you what it means. Some do the arithmetic. One builds and costs a whole camera system. No account, no export limit.
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Showing all 9
Diagnostics
Paste it in,
get a verdict
These take an artifact you already have and tell you something you did not know. No numbers to look up first — the tool does the knowing.
- 01Diagnostic
Switch Config Auditor
Paste a running-config, get the findings.
Paste a switch running-config and get back what an engineer would flag on a handover review: telnet still reachable, default SNMP communities, users on VLAN 1, access ports with no port security or BPDU guard. Every finding cites its line and includes the config that fixes it.
Who reaches for itAnyone inheriting a switch they did not configure, or checking their own work before a floor date.
Open - 02Diagnostic
Drive Health Reader
Paste smartctl output, get a straight answer.
Paste smartctl output for a SATA disk or an NVMe drive and get a verdict rather than a table of numbers. Distinguishes reallocated sectors from pending ones, flags when a drive reports PASSED while actively failing, and tells you when CRC errors mean the cable rather than the disk.
Who reaches for itAnyone deciding whether a drive gets replaced tonight, next month, or not at all.
Open - 03Diagnostic
Traceroute Reader
Paste a trace, find out whose problem it is.
Paste traceroute, tracert, or mtr output and get the path interpreted: where sustained loss actually starts, which hops are only dropping probes cosmetically, whether a latency jump is distance or a fault, and where your network ends and the carrier's begins.
Who reaches for itAnyone about to open a carrier ticket, or about to be told the problem is on their end.
Open
Calculators
Numbers in,
answer out
Sizing work. Each one states its assumptions underneath, because a number without a method behind it is a guess with extra decimal places.
- 01Calculator
Subnet Calculator
CIDR in, everything else out.
Enter an address and a prefix and get the network, broadcast, mask, wildcard, usable host range, and host count. Split a block into equal subnets, or check whether an address falls inside one. Includes a full CIDR reference table.
Who reaches for itAnyone carving up address space or checking someone else's arithmetic before a cutover.
Open - 02Calculator
PoE Budget Planner
Will the switch actually carry the load?
Add up powered devices by PoE class or measured draw, account for cable loss over distance, and compare the total against your switch's power budget. Shows headroom, per-port averages, and whether you are about to brown out an access layer.
Who reaches for itAnyone hanging cameras or access points off a switch and hoping the budget covers it.
Open - 03Calculator
Camera Storage Calculator
How many terabytes for how many days.
Size an NVR or VMS from camera count, resolution, frame rate, codec, retention window, and how much of the day actually records. Returns raw storage, a RAID-adjusted figure, and per-camera daily volume.
Who reaches for itAnyone quoting a surveillance system and needing a defensible storage number.
Open - 04Calculator
Transfer Time Calculator
How long the migration window really needs to be.
Work out how long moving a given volume of data takes over a given link — with realistic protocol overhead and, crucially, the latency limit that actually decides a WAN transfer. A single TCP stream can only carry one window of data per round trip, so a fat pipe sits half idle across distance. Model the round-trip, the TCP window, and parallel streams, then compare link speeds to see exactly where an upgrade stops buying you anything.
Who reaches for itAnyone planning a data migration, cloud sync, backup seed, or overnight cutover — especially over a WAN.
Open
Planners
Build it,
then cost it
Whole-system tools. Configure a design and watch the bill of materials, the storage, and the power budget move with it — the calculators, wired together into one estimate.
- 01Planner
Camera System Estimator
Every part of a camera system, costed.
Build a full CCTV system and get a real bill of materials down to the line item. Add cameras by type and count, set retention, and it sizes the storage array, allocates the PoE budget, picks the switch and recorder, adds mounts, cabling, and labor, and totals it. Storage and PoE are computed by the same engines as the storage and PoE tools, and every price is yours to edit.
Who reaches for itAnyone quoting or budgeting a surveillance system and needing a defensible number, line by line.
Open - 02Planner
Site Plan Designer
Plot devices on a plan, measure, export.
Import a floor plan or schematic and lay out the system on top of it. Drop cameras, recorders, switches, and access points, connect them with cable runs, and set a scale by tracing one known distance so every run measures its own length. Export the marked-up plan as an image, an SVG, or a project file — and send the cameras and their measured cable straight to the Camera System Estimator for a costed bill of materials.
Who reaches for itAnyone planning where devices go and how far the cable runs before anyone climbs a ladder.
Open
Why these exist
Every one of these started as a formula in a notes app, worked out on a job where getting it wrong would have meant a second trip.
The PoE planner exists because a switch datasheet quotes a budget and a camera datasheet quotes a draw, and the number that actually matters is neither — it is the class allocation, which nobody prints. The traceroute reader exists because half the carrier tickets we have opened were argued over loss at a single hop that was never real loss. The drive reader exists because a disk will happily report PASSED while it is dying. So they are free, they show their working, and there is no upsell attached.
- No account, no email gate, no export limit.
- Nothing you enter is stored, ever.
- Everything computes in your browser, with one exception: traceroute hop ownership, which is opt-in and labelled.
- Every assumption is stated on the page.
- Planning figures, not guarantees — buy the next size up when retention is contractual.
Talk to a technician
Happy to run the numbers with you
If you are sizing something real and want a second opinion on it, call. No charge for the conversation, and no obligation after it.
- Free tools
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- Free for everyone