Shutdown & Poweroff Lubuntu
With the stock setting, the network interface stays powered on after a shutdown/poweroff (certainly in order to make a wake-on-lan possible) - LED are lighting.

Grub

$ sudo nano /etc/default/grub
...
GRUB_CMDLINE_LINUX_DEFAULT="splash quiet noacpi"
...

ethtool

$ sudo ethtool eno1       // for interface "eno1". Should give...
...
Wake-on: d
....

If “Wake-on: g” for exemple:

$ sudo ethtool -s eno1 wol d