Wake-on-LAN Instructions (Linux)

On device that needs to be remotely woken

Requirements

sudo apt install ethtool

Setup

See network interfaces (NIC's)
```
ip link show
```
Select the default one (state up, not loop back, usually eth0, eth1, etc.)
See WoL status
```
sudo ethtool <NETWORK-DEVICE-NAME>
```
- If Supports Wake-on has a g character, then it is supported.
- If it does not, then you can swiftly exit this tutorial, as you can not wake-on-LAN the device you want to :(
See if Wake-on is g. It can be any of the following:

Source: https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/6/html/deployment_guide/s1-ethtool
- p — Wake on PHY activity.
- u — Wake on unicast messages.
- m — Wake on multicast messages.
- b — Wake on broadcast messages.
- g — Wake-on-Lan; wake on receipt of a "magic packet".
- s — Enable security function using password for Wake-on-Lan.
- d — Disable Wake-on-Lan and clear all settings.
If not g, then run the following to set it:
```
sudo ethtool -s <NETWORK-DEVICE-NAME> wol g
```

Set WoL status every-time on boot to g

/etc/systemd/system/wol.service:

[Unit]
Description=Enable Wake-on-LAN
Wants=network-online.target
After=network.target network-online.target # <-- `network.target` is optional, backwards compatibility

[Service]
Type=oneshot
ExecStart=/usr/bin/sudo /usr/local/bin/set-wol.sh
User=root

[Install]
WantedBy=multi-user.target

/usr/local/bin/set-wol.sh:

#!/bin/bash

DEV=<NETWORK-DEVICE-NAME>
SLEEP_S=10
MAX_RETRIES=50
RETRY_COUNT=0

while ! ip link show $DEV | grep -q "state UP" && [ $RETRY_COUNT -lt $MAX_RETRIES ]; do
    sleep $SLEEP_S
    ((RETRY_COUNT++))
done

if ip link show $DEV | grep -q "state UP"; then
    /usr/bin/sudo /usr/sbin/ethtool -s $DEV wol g
else
    echo "Failed to bring up $DEV after $MAX_RETRIES attempts."
    exit 1
fi

Note: I tried to simply make the ExecStart in the systemd service: /usr/bin/sudo /usr/sbin/ethtool -s <NETWORK-DEVICE-NAME> wol g, but it didn't seem to work.

It might come down to the NIC not being up yet, because of either 1. standard boot procedures or 2. disk decryption (which I have).

Then, run the following to start the service:

sudo chmod +x /usr/local/bin/set-wol.sh
sudo systemctl daemon-reload
sudo systemctl enable wol.service
sudo systemctl start wol.service

Check sudo systemctl status wol.service and sudo ethtool <NETWORK-DEVICE-NAME> to verify.

Get the MAC address of the device
```
ip addr show <NETWORK-DEVICE-NAME> | grep ether | awk '{print $2}'
```
Save this, since you will need this on all other LAN devices that need to magically boot this device.

On device that wakes remote device

Requirements (Linux)

sudo apt install wakeonlan

Requirements (Windows)

winget install --id=DarkfullDante.wol  -e

Setup (Linux)

wakeonlan <MAC-ADDRESS>

Setup (Windows)

wol -m "<MAC-ADDRESS>"

Conclusion

Done! Can further automate this, e.g. making a powershell/bash script to automatically WoL + decrypt disk upon trying to SSH to the device, by mapping domain names to MAC addresses. But that is niche enough and fairly easy which is outside the scope of this note.