Enable Wake-on-LAN on Fedora with a Realtek r8169 NIC

Steps#

1. Save the script as enable-wol.sh. It walks every active wired connection, sets 802-3-ethernet.wake-on-lan magic in NetworkManager (stored in the connection, applied on every activation) and wol g with ethtool (applied now, no reconnect), then prints both values back.

   #!/bin/bash
   # Enable Wake-on-LAN (magic packet) on the wired NetworkManager connection. Run as root.
   # Persistent: NM applies it on every activation. Immediate: ethtool, no reconnect.
   set -euo pipefail
   E=$(command -v ethtool || echo /usr/sbin/ethtool)
   nmcli -t -f NAME,DEVICE,TYPE c show --active | while IFS=: read -r n dev t; do
     [ "$t" = 802-3-ethernet ] || continue
     nmcli c modify "$n" 802-3-ethernet.wake-on-lan magic
     "$E" -s "$dev" wol g
     echo "$(hostname) $dev '$n': nm=$(nmcli -g 802-3-ethernet.wake-on-lan c show "$n") $("$E" "$dev" | grep -E '^\s*Wake-on:' | xargs)"
   done
   

2. Run it as root.

   sudo bash ./enable-wol.sh
   

   Expected: one line per wired connection, in the form <hostname> <IF> '<CONN>': nm=<VALUE> Wake-on: <LETTERS>, ending in nm=magic Wake-on: g. All four hosts printed that ending. I did not keep the full lines, so none is shown here. The script runs with set -euo pipefail: if a command fails, it stops there with a non-zero exit, without a line for that connection.
3. Power the host off.

   sudo systemctl poweroff
   

   Expected: the host shuts down. Leave its power cable in: Wake-on-LAN needs standby power at the NIC.
4. Send the magic packet from the router.

   /tool/wol mac=<MAC> interface=<BRIDGE>
   

   Expected: the host powers on and boots. In my test I powered two hosts off at 22:45:53, sent the packet at 22:46:21, and they booted at 22:46:40 and 22:46:45, 19 s and 24 s after the packet. If it stays off: see Failure modes, row 1.