TROUBLESHOOTING.md

Troubleshooting

Common issues encountered when using this library, and how to resolve them.

Device does not respond on port 80 (local API offline)

Reported in #577 where a P110 device has been upgraded to firmware 1.4.6. Might apply to other devices, firmware versions and scenarios.

Symptoms

• Connection attempts fail with errors such as error sending request for url (http://<device ip>/app).
• The device responds to pings and works fine in the Tapo app, but a port scan shows that port 80 (HTTP) is closed, and navigating to http://<device ip>/app in a browser times out instead of returning 200 OK.
• The device worked previously and stopped after a firmware update or a power loss.

Cause

Some devices use lazy initialization for their local API service. After booting, the device prioritizes core functions and connects to Wi-Fi and the cloud, but only starts the local web server on port 80 after receiving a TDP (TP-Link Discovery Protocol) probe packet on UDP port 20002.

Solutions

Try these in order:

1. Trigger a TDP (TP-Link Discovery Protocol) probe packet to be sent to the device. This should bring the local API online within a few seconds. Either of these options will do it:
   • Run the tapo_discover_devices.rs example.
   • Refresh the device list in the Tapo app.
2. Factory reset the device. As a last resort, reset the device to factory settings, remove it from the Tapo app, and set it up again.