Verify BIOS/UEFI Settings

Most motherboards require that Wake-on-LAN be enabled in the BIOS or UEFI settings. To check this:

1. Restart the server and enter the BIOS/UEFI settings (usually by pressing a key like Delete, F2, or F10 during boot).
2. Look for an option labeled "Wake-on-LAN," "Power On by PCI-E/PCI," or something similar. This setting needs to be enabled.
3. Save and exit the BIOS.

Confirm and enable Wake-on-LAN Setting with ethtool

First identify which interface to assign for wake-on-lan.

ifconfig

Then identify if the interface has wake-on-lan enabled:

# sudo apt install ethtool
sudo ethtool <interface>

You should see Wake-on: g. If it's set to d, you'll need to enable it again:

sudo ethtool -s <interface> wol g

Make setting persistent

sudo nano /etc/netplan/01-network-manager-all.yaml

Set configuration:

network:
	version: 2
	ethernets:
	  <interface>:
	    dhcp4: false
	    wakeonlan: true
	    addresses:
	      - 192.168.80.91/24
	    routes:
	      - to: default
	        via: 192.168.80.1
	    nameservers:
	      addresses:
	        - 8.8.8.8
	        - 1.1.1.1
	    renderer: NetworkManager

sudo netplan try # To diagnose any issues in yaml file
sudo netplan apply

Running wakeonlan

You can now:

sudo systemctl suspend

the server machine. And from another machine in the network you can:

wakeonlan <MAC>

to wake the server.