Wake-on-LAN

Depending on the hardware, the network driver may have WoL switched off by default.

To query this status or to change the settings, install ethtool, determine the name of the network interface, and query it using the command:

# ethtool ''interface'' | grep Wake-on

Supports Wake-on: pumbag
Wake-on: d

The Wake-on values define what activity triggers wake up: d (disabled), p (PHY activity), u (unicast activity), m (multicast activity), b (broadcast activity), a (ARP activity), and (magic packet activity). The value is required for WoL to work, if not, the following command enables the WoL feature in the driver:

# ethtool -s interface wol g

This command might not last beyond the next reboot and in this case must be repeated via some mechanism. Common solutions are listed in the following subsections.

Link-level configuration is possible through systemd-networkd#link files. The actual setup is performed by the udev builtin. Add the option to the network link file:

/etc/systemd/network/50-wired.link

[Match]
MACAddress=''aa:bb:cc:dd:ee:ff''

[Link]
NamePolicy=kernel database onboard slot path
MACAddressPolicy=persistent
'''WakeOnLan=magic'''

Also see systemd.link(5) for more information.

This is an equivalent of previous option, but uses a standalone systemd service.

Alternatively install the package, then activate this new service by starting .

udev is capable of running any command as soon as a device is visible. The following rule will turn on WOL on all network interfaces whose name matches . The file name is important and must start with a number between 81 and 99 so that it runs after , which renames interfaces with predictable names. Otherwise, would be undefined and the rule would not run.

The $name placeholder will be replaced by the value of the variable for the matched device.

A command can be run each time the computer is (re)booted using "@reboot" in a crontab. First, make sure cron is enabled, and then edit a crontab for the root user that contains the following line:

@reboot /usr/bin/ethtool -s interface wol g

If using netctl, one can make this setting persistent by adding the following the netctl profile:

/etc/netctl/''profile''

ExecUpPost='/usr/bin/ethtool -s ''interface'' wol g'

NetworkManager provides Wake-on-LAN ethernet support. One way to enable Wake-on-LAN by magic packet is through nmcli.

First, search for the name of the wired connection:

By following, one can view current status of Wake-on-LAN settings:

Enable Wake-on-LAN by magic packet on that connection:

# nmcli c modify "wired1" 802-3-ethernet.wake-on-lan magic

Then reboot, possibly two times. To disable Wake-on-Lan, substitute with .

The Wake-on-LAN settings can also be changed from the GUI using .

You can disable Wake-on-Lan for all connections permanently by adding a dedicated configuration file :

When using TLP for suspend/hibernate, the setting should be set to in to allow resuming the computer with WoL.

If you are connected directly to another computer through a network cable, or the traffic within a LAN is not firewalled, then using Wake-on-LAN should be straightforward since there is no need to worry about port redirects.

In the simplest case the default broadcast address is used:

$ wol target_MAC_address

To broadcast the magic packet only to a specific subnet or host, use the switch:

$ wol -i target_IP target_MAC_address

When the source and target computers are separated by a NAT router, different solution can be envisaged:

• If the router supports WoL, one can rely on it to properly broadcast the packet into the local network.

Otherwise Wake-on-Lan can be achieved via port forwarding. The router needs to be configured using one of these two options:

• Forward a different port to each target machine. This requires any target machine to have a static IP address on its LAN.
• Forward a single port to the broadcast address. Most routers do not allow to forward to broadcast, however if you can get shell access to your router, through telnet, ssh, serial cable or other mean, run the command: This example assumes the network is 192.168.1.0/24 and uses net0 as network interface. Now, forward UDP port 9 to 192.168.1.254. This solution was successfully tested on a Linksys WRT54G running Tomato, and on the Verizon FIOS ActionTec router. For notes on how to do it on a router with DD-WRT firmware, see this tutorial and for a router with OpenWrt firmware, see this tutorial.

In any case, run the following command from the source computer to trigger wake-up:

$ wol -p forwarded_port -i router_IP target_MAC_address

In order to make sure the WoL packets reach the target computer, one can listen to the UDP port, usually port 9, for magic packets. The magic packet frame expected contains 6 bytes of FF followed by 16 repetitions of the target computer's MAC (6 bytes each) for a total of 102 bytes.

This can be performed by installing on the target computer and using the following command:

# nc --udp --listen --local-port=9 --hexdump

Then wait for the incoming traffic to appear in the terminal.

Install on the target computer and type the following command:

# ngrep '\xff{6}(.{6})\1{15}' -x port 9

Here is a script that illustrates the use of with different machines:

Setting auto negotiation to may help if WOL is configured through nmcli and network adapter is still powered off on shutdown.

Set it using:

# nmcli c modify "wired1" 802-3-ethernet.auto-negotiate yes

It is known that some motherboards are affected by a bug that can cause immediate or random wake-up after a shutdown whenever the BIOS WoL feature is enabled (as discussed in this thread for example).

The following actions in the BIOS preferences can solve this issue with some motherboards:

1. Disable all references to xHCI in the USB settings (note this will also disable USB 3.0 at boot time)
2. Disable EuP 2013 if it is explicitly an option
3. Optionally enable wake-up on keyboard actions

The issue can also be solved by adding the following kernel boot parameter: This activates the following quirks:

• XHCI_SPURIOUS_REBOOT

Some laptops have a battery draining problem after shutdown . This might be caused by enabled WOL. To solve this problem, disable it by using ethtool as mentioned above.

# ethtool -s net0 wol d

Users with Realtek 8168 8169 8101 8111(C) based NICs (cards / and on-board) may notice a problem where the NIC seems to be disabled on boot and has no Link light. See Network configuration/Ethernet#Realtek no link / WOL problem.

If the link light on the network switch is enabled when the computer is turned off but wake on LAN is still not working, booting the system using the kernel module at least once and then switching back to the r8169 kernel module included with the kernel seems to fix it at least in the following configurations:

• MSI B85M-E45 motherboard, BIOS version V10.9, onboard Realtek 8111G chipset

For the r8168 module you might need to set the module option to enable the wake on LAN functionality.

For some newer Atheros-based NICs (such as Atheros AR8161 and Killer E2500), WOL support has been disabled in the mainline module due to a bug causing unintentional wake-up (see this patch discussion). A patch can be applied (or installed as a dkms module using the package) which both restores WOL support and fixes the underlying bug, as outlined in this thread.

See also the pre-patched sources in .