routine
An inventory that stays true
A one-page method for keeping a device list that still matches reality six months from now — using any of the scanners on this site.
01The problem with one-off scans
Anyone can run a sweep once. The list is accurate for exactly as long as nothing changes — which, on a network with phones that rejoin WiFi and laptops that come and go, is about a day. The value is not in the scan; it is in the comparison between this scan and the last one.
02The monthly loop
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Sweep on a schedule
Same day each month, same tool, same range. Angry IP Scanner exporting CSV is enough; consistency matters more than the choice of tool.
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Name what you recognise
Open the CSV and fill a column called "what is this" for every MAC you know: living-room TV, printer, laptop. Unknowns stay blank — on purpose.
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Diff against last month
Any spreadsheet tool compares the MAC columns. Three kinds of rows matter: new MACs, gone MACs, and known MACs that moved to a different address.
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Investigate the differences, not the list
A new MAC is a new gadget or a guest; identify it once and it stops being noise. A gone MAC is a broken device or a replaced one. The moving MAC is usually a DHCP lease renewal — ignore those.
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Keep the folder, lose nothing
Twelve CSVs with dates are a year of network history. When something breaks in October, the March file tells you what the network looked like when it last worked.
03Why devices "disappear"
- Phones and laptops sleep aggressively; a sleeping device answers nothing. Sweep twice, an hour apart, before declaring it gone.
- Guest networks and client isolation hide devices from the main LAN scanner by design. That is a feature, not a fault.
- Anything behind a different router — a second subnet, some mesh extensions — is a separate range that needs its own sweep.
Do this loop for three months and the question "who is on my network" stops being a surprise every time. That is the entire promise of this site, kept.