How To Wake Up Computers Using Linux Command [ Wake-on-LAN ( WOL ) ] By Sending Magic Packets

Wake-on-LAN (WOL) is an Ethernet networking standard that allows a server to be turned on by a network message. You need to send ‘magic packets’ to wake-on-lan enabled ethernet adapters and motherboards to switch on the called systems. Make sure you connect the NIC (eth0 or eth1) with the motherboard and enable the BIOS’s WOL function. This is a quick guide to enable WOL under RHEL / Fedora / CentOS / Debian / Ubuntu Linux.

Client Software

It would be best if you used software to send WoL magic packets to the target system. You will find various tools for all modern oses, including MS-Windows, Apple macOS/OS X, Linux, and many smartphones.

Linux Install etherwake Under Debian / Ubuntu Linux

We use the etherwake command to send a Wake-On-LAN “Magic Packet” under Linux operating systems. Type the following apt-get command/apt command to install the same under Debian / Ubuntu Linux desktop:
## apply all patches on Debian/Ubuntu ##
$ sudo aptitude install etherwake
## OR ##
$ sudo apt install etherwake

Session:

[sudo] password for vivek: 
Reading package lists... Done
Building dependency tree       
Reading state information... Done
E: Unable to locate package etherwak
[vivek@nixcraft-wks01 backups]$ sudo apt install etherwake
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following additional packages will be installed:
  wakeonlan
The following NEW packages will be installed:
  etherwake wakeonlan
0 upgraded, 2 newly installed, 0 to remove and 0 not upgraded.
Need to get 18.1 kB of archives.
After this operation, 56.3 kB of additional disk space will be used.
Do you want to continue? [Y/n] y
Get:1 http://archive.ubuntu.com/ubuntu focal/universe amd64 etherwake amd64 1.09-4build1 [8,900 B]
Get:2 http://archive.ubuntu.com/ubuntu focal/main amd64 wakeonlan all 0.41-12 [9,232 B]
Fetched 18.1 kB in 1s (16.9 kB/s)    
Selecting previously unselected package etherwake.
(Reading database ... 338929 files and directories currently installed.)
Preparing to unpack .../etherwake_1.09-4build1_amd64.deb ...
Unpacking etherwake (1.09-4build1) ...
Selecting previously unselected package wakeonlan.
Preparing to unpack .../wakeonlan_0.41-12_all.deb ...
Unpacking wakeonlan (0.41-12) ...
Setting up wakeonlan (0.41-12) ...
Setting up etherwake (1.09-4build1) ...
Processing triggers for man-db (2.9.1-1) ...

Installing a tool to send a Wake-On-LAN “Magic Packet” on RHEL/CentOS Linux

There is also Perl script to wake up computers. We can install it as follows on Debian/Ubuntu Linux:
sudo apt-get install wakeonlan

Type the following dnf command/yum command on your Fedora/RHEL/CentOS system. For instance:
$ sudo yum install net-tools
Outputs from my RHEL 8 box:

Last metadata expiration check: 3:23:23 ago on Mon Feb 22 05:56:16 2021.
Dependencies resolved.
================================================================================
 Package         Architecture Version                        Repository    Size
================================================================================
Installing:
 net-tools       x86_64       2.0-0.52.20160912git.el8       baseos       322 k
 
Transaction Summary
================================================================================
Install  1 Package
 
Total download size: 322 k
Installed size: 942 k
Is this ok [y/N]: y
Downloading Packages:
net-tools-2.0-0.52.20160912git.el8.x86_64.rpm   689 kB/s | 322 kB     00:00    
--------------------------------------------------------------------------------
Total                                           271 kB/s | 322 kB     00:01     
Running transaction check
Transaction check succeeded.
Running transaction test
Transaction test succeeded.
Running transaction
  Preparing        :                                                        1/1 
  Installing       : net-tools-2.0-0.52.20160912git.el8.x86_64              1/1 
  Running scriptlet: net-tools-2.0-0.52.20160912git.el8.x86_64              1/1 
  Verifying        : net-tools-2.0-0.52.20160912git.el8.x86_64              1/1 
 
Installed:
  net-tools-2.0-0.52.20160912git.el8.x86_64                                     
 
Complete!

Red Hat Linux and friends users should use the net-tools package, which may be installed by default. The command name is ether-wake.

How Do I Send WOL Magic Packets Under Linux?

Type the following command:
# wakeonlan MAC-Address-Here
OR
# etherwake MAC-Address-Here
# etherwake -D MAC-Address-Here

RHEL / Centos / Fedora Linux user, try:
# ether-wake MAC-Address-Here
If your MAC address were xx:yy:zz:11:22:33, you would type:
# wakeonlan xx:yy:zz:11:22:33
OR
# etherwake xx:yy:zz:11:22:33
Where,

  • xx:yy:zz:11:22:33 is remote servers mac address. You can obtained mac address using combination of the ping command and arp command:
    ping -c 4 server3 && arp -n

How Do I Verify That Remote Linux Server Supports Wake-on-LAN (WOL)?

First, reboot the remote server and go to BIOS > Power Management > “Wake On LAN”. Please turn WoL on. Next, save and close the bios settings. After activating Wake On LAN (WoL) in your BIOS hardware option for the network interface card, it is also necessary to activate it using ethtool. The ethtool command will configure eth0 to respond to the magic packet:
# ethtool -s eth0 wol g
Where,

  1. -s eth0 : Your NIC. Feel free to replace eth0 with your actual network interface device name.
  2. wol g : Sets Wake-on-LAN options using MagicPacket.

Type the following command to see current status of wol for eth0:
# ethtool eth0
Output from my NAS server:

Settings for eth0:
	Supported ports: [ ]
	Supported link modes:
	Supports auto-negotiation: No
	Advertised link modes:  Not reported
	Advertised auto-negotiation: No
	Speed: 100Mb/s
	Duplex: Full
	Port: MII
	PHYAD: 1
	Transceiver: internal
	Auto-negotiation: off
        Supports Wake-on: g
       Wake-on: g
	Link detected: yes

If you are using RHEL / SL / Fedora / CentOS Linux, edit /etc/sysconfig/network-scripts/ifcfg-eth0:
# vi /etc/sysconfig/network-scripts/ifcfg-eth0
Add / modify the following line:

ETHTOOL_OPTS="wol g"

OR

ETHTOOL_OPTS="wol g autoneg off speed 100 duplex full "

Save and close the file. If you are using Debian / Ubuntu Linux, edit /etc/network/interfaces:
# vi /etc/network/interfaces
Append the following to eth0:

auto eth0
iface eth0 inet static
address 192.168.1.1
netmask 255.255.255.0
gateway 192.168.1.254
        post-up /sbin/ethtool -s eth0 wol g
        post-down /sbin/ethtool -s eth0 wol g

Summing up

I explained how to set ‘magic packets’ to wake-on-lan (WoL) enabled ethernet adapters and motherboards to switch on the PC or server. The magic packets also work when your system is in suspend or deep sleep mode. For example, my backup FreeBSD server can wake up my laptop at midnight and backup files. Of course, your BIOS must support the WoL option. Otherwise, it will not work. Recommend readings:


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🐧 14 comments so far... add one

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14 comments… add one
  • Pulipuli Mar 25, 2017 @ 4:15

    Very useful. Thanks.

  • Ahmed Feb 5, 2016 @ 8:03

    HI,
    One useful bash script if you want to automate WOL wake and inform user depending on the stats of it.
    ————————————————————————–
    NOTE: “hppl-1” is the hostname in the script
    ==========================================

    #!/bin/bash
    VAR=`ping -s 1 -c 2 hppl-1 > /dev/null; echo $?`
    if [ $VAR -eq 0 ];then
    echo -e "hppl-1 is UP as on $(date)"
    elif [ $VAR -eq 1 ];then
    wakeonlan 9c:b6:12:09:8d:22 | echo "hppl-1 not turned on. WOL packet sent at $(date +%H:%M)"
    sleep 3m | echo "Waiting 3 Minutes"
    PING=`ping -s 1 -c 4 hppl-1 > /dev/null; echo $?`
    if [ $PING -eq 0 ];then
    echo "hppl-1 is UP as on $(date +%H:%M)"
    else
    echo "hppl-1 not turned on - Please Check Network Connections"
    fi
    fi

    =====================================================
    Saw this on this website www. howtovmlinux .com

    Regards,
    Ahmed

  • Roger Jollie Mar 22, 2013 @ 22:46

    If you want to shut down or reboot a remote computer such as a Windows box you can do the following:

    net rpc shutdown -I ip or name of computer -U username%password

    If you don’t want to have the password in plain text on the screen omit the %password and you will be prompted for it. if you use a -r switch the computer will reboot. If you are on a domain network you can use your domain account by using the following

    domain/username

  • Simon Apr 27, 2012 @ 13:35

    Hey there.
    I am searching for a way to send a magic packet with wakeonlan on startup, after the network is there. I already wrote a script but that doesn´t work on startup. The stop-command works though, so the command I give is right. Don´t know what I am doing wrong.

    • 🐧 nixCraft Apr 29, 2012 @ 8:52

      Can you paste your script using pre tags here?

    • Rich May 18, 2014 @ 15:23

      Did you ever figure this out? I’m trying to do the same thing.

  • Nora Apr 18, 2012 @ 5:55

    Should be possible, yes. But then I’d rehatr do a management interface where you can add all the MACs you possible want to wake and make the other thing a drop down menu. This would separate the admin from the user which may be a good thing.

  • Dan Apr 8, 2012 @ 20:50

    Shutdown a linux machine with : “sudo halt “.
    Of course it can work without sudo if you have enough user rights.. ( see doc/ groups)

    WOL is only for wake.

  • zam Apr 4, 2012 @ 15:44

    Hi

    can any one please tell me How to shutdown the Computers Using Linux Command [ Wake-on-LAN ( WOL ) ]

    • Alex May 8, 2012 @ 21:32

      ssh into the box and, as root, “shutdown -h now”

      • Ion Jan 27, 2015 @ 19:20

        or poweroff

  • Russell Gadd Apr 4, 2012 @ 8:53

    I’m no expert but looking at Synaptic there is also a wakeonlan command which can be installed.

    In the Synaptic blurb for this package it says:
    You need the MAC addresses of machines to construct the WOL packets, but,
    in contrast to ‘etherwake’, you do not need root privileges to use the
    program itself as UDP packets are used.

    • 🐧 nixCraft Apr 4, 2012 @ 10:53

      Yes, wakeonlan can be run as non-root user, but etherwake must run as root.

  • anand vamsi Apr 4, 2012 @ 3:41

    really a helpful command need to experiment.

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