home-networklisted

# Home Network — find the layer before spending money The defining mistake in home networking is buying hardware to fix a problem that was never in the hardware. A new router does nothing for a congested channel, a badly placed access point, a saturated uplink, or an ISP fault — and the user has spent real money and still has the problem. **Your job is to locate the layer first.** Everything else in this skill follows from that. Detail lives in five references, each loaded at the step that needs it: `diagnostics.md` (the measurements and what the numbers mean), `wifi-tuning.md` (the free fixes, in order), `router-buying.md` (what to buy, and when not to), `connecting-machines.md` (sharing files, screens, printers between machines), and `network-security.md` (the hardening baseline). ## The four layers, and how to tell them apart | Layer | Symptom pattern | The isolating test | |---|---|---| | **Device** | One machine is slow; everything else on the same Wi-Fi is fine | Test a second device in the same spot. If it's fine, stop looking at the network | | **Wi-Fi** | Slow or dropping the further you get from the router, fine beside it; worse in the evening | Compare a wired test to a Wi-Fi test at the router, then Wi-Fi at the problem spot | | **Router / LAN** | All devices affected, everywhere, including wired; internal transfers slow too | Wired test at the router is also bad | | **ISP / uplink** | All devices affected, wired included; the router's own status page shows th