netlanscan · a working manual

Know what plugs into your network

Q: How do I find unknown devices connected to my router?

Feed your subnet's address range to a scanner and compare the live-host list with the gadgets you can physically see. Anything in the table you cannot put a finger on deserves a closer look — and a new WiFi password if it stays a mystery.

Q: Will a network scanner work without installing software?

Angry IP Scanner distributes a portable edition: unpack it, run it, done. It asks for no administrator rights and leaves no traces, which also makes it the usual choice for quick checks on other people's machines.

Q: Can scanning my own network get me in trouble?

No — auditing gear you own or are responsible for is standard practice. Aiming the same tools at networks you have no mandate over can violate the law in most countries, so keep the sweeps inside your own walls.

Q: Why do phones and TVs disappear from scan results?

Modern gadgets save battery by ignoring ping packets entirely. Scanners that cross-check the ARP table still see them, since the device must answer ARP to use the network at all.

Three scanners, three budgets, one goal: a trustworthy list of everything connected to your LAN. This manual explains what each tool reveals, how to run it without ceremony, and when paying for a licence is actually justified.

revised 15 september 2026 · independent, unaffiliated

ch. 1The premise

Routers ship with a client list, and that list is wrong more often than it is right. Devices rename themselves, go to sleep, or simply never registered. A scanner asks the network directly — address by address, "is anybody there?" — and the answer it assembles is the closest thing to truth you can get without console cables.

The three programs in this manual overlap on the basics and diverge sharply on the rest. One is free and portable. One is built for Windows offices and their shared folders. One is a licensed kit for people who document networks for a living.

Angry IP Scanner

The pocket torch. Unzip, point at a range, and a minute later you have every live host with names and MACs.

licence free, open source platforms windows, macos, linux reveals live hosts, hostnames, MACs, ports

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LizardSystems Network Scanner

The office auditor. Enumerates every computer, printer and shared folder — and tests how open each share really is.

licence free edition + paid platforms windows reveals computers, shares, printers, access rights

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Engineer's Toolset

The draughtsman's kit. SNMP-driven discovery that ends in a switch-port map suitable for archiving.

licence paid, per engineer platforms windows reveals topology, port maps, VLANs, MAC tables

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ch. 2Choosing in thirty seconds

One-off question at home — Angry IP Scanner. Zero cost, zero install, answer before the tea cools.
Small office on Windows with shared folders — LizardSystems Network Scanner; its permission check alone justifies the download.
You invoice for network documentation — Engineer's Toolset. Port maps and MAC tables in vendor-grade form.

Undecided? Read the comparison chapter — four minutes, no fluff — and once the sweeps become routine, adopt the monthly census.

ch. 3Common questions

How do I find unknown devices connected to my router?

Sweep the subnet your router serves — commonly 192.168.something.0–255 — then walk the house matching table rows to physical gadgets. Rows you cannot account for are either a forgotten gadget or a stranger; only one of the two is comfortable.

Will a network scanner work without installing software?

Yes. Angry IP Scanner ships a portable build: one folder, no setup, no admin rights, no leftovers. It is the standard answer for quick audits on machines you do not own.

Can scanning my own network get me in trouble?

Auditing your own equipment is normal maintenance. Pointing scanners at networks you have no authority over is a criminal matter in many jurisdictions — the line is ownership, and it is not blurry.

Why do phones and TVs disappear from scan results?

Battery-conscious devices ignore ping. Tools that also read the ARP table still catch them, because no device can use the network without answering ARP. If your scanner supports an ARP source, enable it.