WOL dual-boot
published on Wednesday, October 10, 2018
Setting up Wake-on-LAN for your PC may require configuring both your BIOS/UEFI as well as your operating system. If multi-booting more than one OS, it's necessary to set all of them up, since only the last running OS before shutdown determines whether the PC will be listening for magic packets.
I will give a short and comprehensive write-up of all the steps it took for me to make Wake-on-LAN work on a dual-boot system with archlinux and windows 10. While there are already many guides, it is sometimes hard to find all the relevant information in one place.
Linux
On linux, the ethtool program can be used as follows to enable WOL on your network interface for the next shutdown only:
ethtool -s INTERFACE wol g
where INTERFACE is the name of your ethernet adapter as displayed by ip l or found via ls /sys/class/net | grep en, e.g. enp0s25.
However, this setting will be lost after the next reboot! To make it persistent it must be executed again on every reboot. This can be achieved using cronjob, udev rules, systemd units or third-party packages.
Quite unsurprisingly, the archwiki has a great Wake-on-LAN article that explains several alternatives to enable WOL. I will mirror some of the information here, in case the wiki is modified:
cronjob
Use the following cronjob to enable WOL on every reboot:
@reboot /usr/bin/ethtool -s INTERFACE wol g
wol-systemd
The wol-systemd AUR package provides a simple systemd unit for running ethtool. Install the package, then enable and start the unit:
yaourt -S wol-systemd
systemctl enable wol@INTERFACE
systemctl start wol@INTERFACE
NetworkManager
If you're using NetworkManager, you can use enable WOL via nmcli. First, determine the name of your ethernet connection by typing:
nmcli con show
then enable magic packets as follows:
nmcli con modify "NAME" 802-3-ethernet.wake-on-lan magic
Windows
On windows, I ended up consulting several guides and modifying multiple settings before WOL started working. Summary of steps:
Right click the windows icon and open the Device Manager. Navigate to Network Adapters and double-click your ethernet adapter. Then go to the following tabs:
- Power Management:
- [x] Allow this device to wake the computer
- [x] Only allow a magic packet to wake the computer (to prevent waking up from other events)
- Driver: Update Driver and let windows Search automatically for updated driver software. Afterwards reboot. This step may not be needed.
- Advanced: Search the list for an Wake on Magic Packet entry and set it to enabled. If no such entry exists, update the driver and restart first.
Furthermore, you may have to disable the fast startup option in windows (don't worry it will probably not noticably impact startup times):
- Press Win + X and open Power Options
- Click Additional power settings on the right (under related settings)
- Click Choose what the power buttons do on the left menu
- Click Change settings that are currently unavailable
- Scroll to Shutdown settings
- Uncheck Turn on fast startup (recommended)
Of course, they're changing the names and location of these settings on seemingly every update, so good luck to you and future me;)
UEFI
Besides OS settings, it is usually necessary to enable WOL in UEFI as well. The following settings are those that were necessary for me to touch to make WOL finally work. Naturally, these options may be named differently, reside in different sections, or may not even exist in your UEFI.
- Enable Boot -> Boot From Onboard LAN
- Disable Boot -> Fast Boot
- Enable Advanced -> ACPI Configuration -> PCIE Devices Power On
Check packet reception
If WOL just doesn't want to start working, you can check whether the the target machine receives the magic packet with gnu-netcat:
nc --udp --listen --local-port=40000 --hexdump
In this case, also make sure use the same port while sending the packet (wol -p PORT option). If you choose a protected port such as 9 you will need root permissions for the netcat command above.
Alternatively, with wireshark once you've been added to the wireshark group (and logged out and in again), you can listen in as a user on all WOL packets arriving on arbitrary ports:
tshark -i INTERFACE -Y wol