1. Verify WOL Support

ethtool <interface>

Replace <interface> with the physical NIC, not the bridge (e.g., enp3s0, eth0, etc.). Look for:

Supports Wake-on: pumbg
Wake-on: d

• If Supports Wake-on includes g, then WOL is supported.

• If Wake-on: d, then WOL is disabled.

2. Enable WOL Temporarily (For Testing)

ethtool -s <interface> wol g

This enables WOL (magic packet). But this setting is lost after reboot, so we must persist it.

3. Persist WOL on Boot (Systemd service method)

Create a systemd service to set WOL on boot:

sudo nano /etc/systemd/system/wol.service

Paste the following:

[Unit]
Description=Enable Wake-on-LAN
After=network.target

[Service]
Type=oneshot
ExecStart=/usr/sbin/ethtool -s enp3s0 wol g

[Install]
WantedBy=multi-user.target

Replace enp3s0 with your physical device name.

Then enable the service:

sudo systemctl daemon-reload
sudo systemctl enable wol.service

4. Bridge Considerations

If you're using a bridge like br0, the physical interface (enp3s0) might be enslaved and NetworkManager or systemd-networkd may interfere with WOL.

Ensure the physical NIC is not set to 'managed=no' if using NetworkManager.