Wake On LAN Daemon
Connects to an MQTT server, watches for a message and sends a UDP broadcast with a Wake On LAN payload.
Because if the machine is off for a while, a targeted message will fail because the switch won't be able to find the host.
A broadcast works, but Linux won't forward the message when acting as a router.
MQTT works across subnets, so run something that watches the server to send the wake up message.
Run WOLD on a host that exists on the same subnet as the machine you want to wake up.
wold -h -p
mosquitto_pub -h -t /com/wold/target -m