Overview
Wake-on-Lan (WoL) enables you to turn on your machine remotely. This is ideal if you have machine in another room, like a server in an out of the way place. The machine wakes up when it receives a special message called a magic packet. You can send magic packets from other computers or even from your mobile phone. The message is sent over your network using Wi-Fi or a wired connection.
This article will show you how to enable WoL on your linux machine.
Enable BIOS Power Management Events
For Wake-on-Lan (WoL) to work the BIOS needs to be set to accept Power Management Events (PME). Different vendors might call have a different name for them, but in my Asus BIOS it was labelled Power on by PME.
List network Interfaces
To enable Wake-on-Lan (WoL) you need to find out what your Ethernet Interface is called. This is how your computer connects to your network.
You can use any one of the following methods:-
ip command
This shows or manipulate routing, devices, policy routing and tunnels.
ip link showOn my machine this outputs the following:-
1: lo: <loopback,up,lower_up> mtu 16436 qdisc noqueue state UNKNOWN
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: <broadcast,multicast,up,lower_up> mtu 1500 qdisc pfifo_fast state UP qlen 1000
link/ether 00:xx:yy:xx:yy:z0 brd ff:ff:ff:ff:ff:ff</broadcast,multicast,up,lower_up></loopback,up,lower_up>In the shown output my first Interface is called eth0. If I had two Interfaces the second one would be called eth1, and so on. If I have Wi-Fi installed I might have an interface called wlan0.
netstat command
This diisplays network connections, routing tables, Interface statistics, masquerade connections, and multicast memberships.
netstat -iOn my machine this outputs the following:-
Kernel Interface table
Iface MTU Met RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg
eth0 1500 0 6059317 0 0 0 3277643 0 0 0 BMRU
lo 16436 0 59 0 0 0 59 0 0 0 LRUAgain, in the shown output my first Interface is called eth0.
ifconfig command
This displays or configures a network Interface.
ifconfig -aOn my machine this outputs the following:-
eth0 Link encap:Ethernet HWaddr 00:xx:yy:xx:yy:z0
inet addr:134.111.0.1 Bcast:134.111.0.255 Mask:255.255.255.0
inet6 addr: 00:xx:yy:xx:yy:z0/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:6484950 errors:0 dropped:0 overruns:0 frame:0
TX packets:3474044 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:8097099790 (8.0 GB) TX bytes:1164269136 (1.1 GB)
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:62 errors:0 dropped:0 overruns:0 frame:0
TX packets:62 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:5008 (5.0 KB) TX bytes:5008 (5.0 KB)</code></pre>Again finally, in the shown output my first Interface is called eth0.
Change Interface settings
Now that we know what our Interface is called, in my case eth0, we now need to install a program that can set or update settings on our Interface. The program to do this is called ethtool.
Install ethtool
sudo apt-get update
sudo apt-get install ethtoolThis displays or sets Ethernet device settings.
Once ethtool has been installed you can now use the following command - replace eth0 with the name of your device.
sudo ethtool eth0On my machine this outputs the following:
Settings for eth0:
Supported ports: [ TP MII ]
Supported link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Half 1000baseT/Full
Supported pause frame use: No
Supports auto-negotiation: Yes
Advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Half 1000baseT/Full
Advertised pause frame use: Symmetric Receive-only
Advertised auto-negotiation: Yes
Link partner advertised link modes: 10baseT/Half 10baseT/Full
100baseT/Half 100baseT/Full
1000baseT/Half 1000baseT/Full
Link partner advertised pause frame use: Symmetric Receive-only
Link partner advertised auto-negotiation: Yes
Speed: 1000Mb/s
Duplex: Full
Port: MII
PHYAD: 0
Transceiver: internal
Auto-negotiation: on
Supports Wake-on: pumbg
Wake-on:
Current message level: 0x00000033 (51)
drv probe ifdown ifup
Link detected: yesThe entry Supports Wake-on indicates whether your Interface supports Wake-on-Lan (WoL). The flag for WoL is g. In my example Supports Wake-on has a value of pumg, so my Interface does support Wake-on-Lan.
However, Wake-on currently has no value. So my Interface supports WoL but my Interface is not currently set to Wake-on-Lan (WoL).
Run the following command to enable Wake-on-Lan (WoL). Remember to replace eth0 with the name of your Interface.
sudo ethtool -s eth0 wol gTo see if WoL is now set, re-run this command:-
sudo ethtool eth0You should now see that Wake-on is set to g.
Set WoL to work after reboot
When you restart your machine the Interface will forget the WoL setting. To make sure WoL is always set to g, we need to edit a script that runs every time the machine is turned on.
sudo nano /etc/network/InterfacesOn my machine this outputs the following:-
# This file describes the network Interfaces available on your system
# and how to activate them. For more information, see Interfaces(5).
# The loopback network Interface
auto lo
iface lo inet loopback
# The primary network Interface
auto eth0
iface eth0 inet dhcpAdd the following to the end of the file:-
#allow wol on boot
up ethtool -s eth0 wol gTo save a file opened using nano, do Ctrl + o to output the file and Ctrl + x to exit and return to the command line.
Testing Wake-on-Lan (WoL)
I use an app on my mobile phone called Fing that sends a WoL magic packet to my computer. I highly recommend this app.