Symptom-led checks
Define the blast radius first
Ask whether one device, one room, one connection type, one platform, or the whole home is affected. Record what changed and what still works. This turns “the smart home is down” into a testable boundary.
Symptom-led checks
Symptom to action
| Symptom | Likely layer | Reversible test | Next action |
|---|---|---|---|
| Everything failed after router replacement | LAN identity or infrastructure order | Verify SSID/security and one phone with cellular off. | Restore controllers and bridges before accessories. |
| Device has internet but setup cannot find it | Local discovery or isolation | Move phone and device to the intended main LAN. | Review documented guest/client-isolation rules. |
| Strong Wi-Fi, unreliable commands | Backhaul, discovery, controller, cloud, or rule | Test direct app, platform control, then automation. | Fix the first failing transition. |
| Thread devices fail as a group | Border router or adjacent LAN | Confirm border-router power and another Thread device. | Restore infrastructure; do not reset the group. |
Symptom-led checks
Change one variable
After each test, record the result and make one change. Retest with the same command. Avoid changing SSID, bands, firewall, isolation, accounts, and device state at once; a successful outcome will not tell you which change mattered.
Symptom-led checks
Security boundaries stay in force
Do not expose devices directly to the internet, forward broad port ranges, remove passwords, or disable the firewall to recover local discovery. Use supported LAN and discovery settings, restore secure credentials, and ask the router or device maker for the minimum required path. Factory reset remains a late, model-specific step.
Evidence boundary
Network behavior depends on the exact setup
Router, mesh, platform, model, software, and region behavior can change. Confirm current documentation before changing network security or resetting a device. Never expose devices directly to the internet merely to restore discovery.
Primary sources
Official documentation behind the network boundaries
Continue the diagnosis