How to Wake on LAN?

Hi,
when my Rock Pi S (without WiFi/Bluetooth) is idling several hours, it seems to fall asleep and loses network connection, so I thought I’d wake it up using pywakeonlan or wol to wake it up. So I noticed the MAC address and tested both tools, but it won’t wake up.
If my presumption is right, how do I wake it up?

I am sorry ROCK Pi S doesn’t support WoL on hardware. ROCK Pi S should not go sleep after idling sever hours. You’d better check with a serial console and see what’s happening.

Thanks.

Now I checked it with a serial console and found out a kernel panic.
Since I’m using slarm64, I posted it on Slackware-ARM forum at linuxquestions.org.

For those who are interested, here’s a link: https://www.linuxquestions.org/questions/slackware-arm-108/rock-pi-s-random-kernel-panic-4175686822/

I find this device disappearing from the network after a few days. Also using slarm, kernel 5.10.10.

The only stable kernels I tested so far are 4.4.* on the Rock Pi S. With all 5.* kernels I got regularly kernel panics in slarm64. Now I’m using kernel 4.4.248 with no stability issue.