Summary

I'm using Kasa devices (HS110, HP115, KP125/EP25, HS300) to monitor power consumption and/or provide remote reboot (power cycle) capability in case a connected device becomes unresponsive.

I'd like to be able to monitor for Kasa device reboots, since that results in an unexpected power loss for the connected load. I'm looking to see anyone has any better ideas/solutions to this than I've come up with so far.

The problem

When Kasa devices reboot the connected device will briefly lose power. The reboot can be caused by a firmware update or the Kasa device crashing and rebooting. Unexpected firmware updates can be prevented by blocking Kasa devices from internet access, but that has some side effects.

While I've had a number of years of very reliable performance with devices like the HS110s, I've had problems with recent KP125/EP25 devices spontaneously rebooting. The result is I've spent time investigating why connected computers have rebooted, but couldn't find anything in the logs because the cause was power loss to only that device.

Note: kp125/ep25 firmware issue

(NOTE: This may have been related to the problem KP125 reboots if it can't call home. Firmware 1.0.10 only. I've recently upgraded to 1.0.13, but it will take time to see if that fixes things.)

Question(s)

Is there a way to query a Kasa device to get the uptime (how long since last reboot) or the time it was booted?

Any way to query any sort of device logs or debugging info?

What I've found so far

• Home Assistant (2024.1.x out of the box with the current TP-Link integration) isn't as helpful as I would have thought. I need to look into this more. Home Assistant is even less helpful if it winds up crashing and rebooting because it is controlled by a Kasa plug that causes a brief power interruption.
• DHCP - during reboot the kasa device will have to do a DHCP DISCOVER, so with access to the DHCP' server's logs. However there are other reasons a DHCP client might need to start over with a discover request So, not a perfect indication.
• Using the kasa CLI, if a device is always on the on since: state output will essentially show the last reboot time. The uptime in seconds equivalent is kasa --json --host myplug --type plug state | jq .system.get_sysinfo.on_time. So I should be able to cobble something together that detects when this drops instead of increasing. Or if the value simply falls to less than the polling interval (<= 300 seconds for polling every 5 minutes). While this is probably good enough in many cases, switching off the Kasa plug means it won't show the time of last reboot, but it still gives the desired info of how long the connected device has been powered on for.
• This issue would be mostly solved for me if the Kasa "on since" date time was available as a sensor within Home Assistant that was retained across reboots. (Unfortunately, this info isn't available reliably from the state of the switch entities. For some reason, 9 out of 14 Kasa plug switch entities don't show any history past the most recent Home Assistant restart. I don't know if this might be a bug, or the fact that Home Assistant didn't have a clean shutdown due to power loss.)