It’s been a couple of years since I’ve heard of Wake on LAN (WoL) and today I finally decided to set it up.

What is WoL? Well it allows you to power on a computer over the network, even when the computer is turned off.

WoL Setup Proxmox Host Machine
WoL Setup Proxmox Guest Machines
Verify

WoL Setup Proxmox Host Machine

First we got to enable it in 2 places

in BIOS
in OS

In BIOS

Each computer’s BIOS settings are different, so try to enable something like ‘Wake on LAN (WoL)’. Usually, it should be under the Power Management Tab.

In OS

Install ethtool:

apt install ethtool -y

Show network interfaces

ip addr

Find something that looks like enp114s0 and make note of it. In my case it looks like:

root@pve2:~# ip addr
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 65536 qdisc noqueue state UNKNOWN group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
       valid_lft forever preferred_lft forever
    inet6 ::1/128 scope host noprefixroute
       valid_lft forever preferred_lft forever
2: enp114s0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc mq master vmbr0 state UP group default qlen 1000
    link/ether 48:21:0b:5f:e9:05 brd ff:ff:ff:ff:ff:ff
3: wlo1: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN group default qlen 1000
    link/ether e4:0d:36:09:a1:cd brd ff:ff:ff:ff:ff:ff
    altname wlp0s20f3

Check if WoL is enabled

ethtool enp114s0

Ensure output contains Wake-on: g, something like:

...
    MDI-X: off (auto)
    Supports Wake-on: pumbg
    Wake-on: g
        Current message level: 0x00000007 (7)
                               drv probe link
    Link detected: yes

If it doesn’t contain g then check if it supports it by verifying Supports Wake-on: pumbg

If supported then enable it:

Temporary Enable

The following command only lasts one computer restart :/

ethtool -s enp114s0 wol g

Permanent Enable

Create a service file /etc/systemd/system/wol.service with the following

[Unit]
Description=Enable Wake On Lan
 
[Service]
Type=oneshot
ExecStart = /usr/sbin/ethtool --change enp12s0 wol g
 
[Install]
WantedBy=basic.target

Execute the following

sudo systemctl daemon-reload
sudo systemctl enable wol.service
systemctl status wol

Now WoL is configured on your Proxmox Host Machine!

WoL Setup Proxmox Guest Machines

Sometimes you want to WoL your guest machines within the Proxmox Host Machine!

Based on: https://github.com/djraw/pve-dosthol

Install dependencies

apt install gawk socat xxd

Add the following file into /usr/local/bin/dosthold.sh:

#!/bin/bash
 
# dosthol - Do something on LAN
#   Skript to do something with remote virtual machines
#   Written primarily for Proxmox VE >=v4.x
#
# Author: Oliver Jaksch <proxmox-forum@com-in.de>
#
# Daemon changelog:
#   v0.7 (2020-12-02) - Fixup dependency check, added Reboot command, changed from GPLv2 to GPLv3
#   v0.6 (2020-12-02) - Check for missing dependencies
#   v0.5 (2019-03-17) - Beautify shell execs, limit grep to find only one result (thanks cheffe)
#   v0.4 (2017-01-03) - Expanded Resume: Send a key before resume (Windows Standby)
#   v0.3 (2016-03-11) - Fixed typo in dosthol.service
#   v0.2 (2016-03-07) - Renamed dosthol to dosthold, created client dostholc, finished more commands, turned to socat
#   v0.1 (2016-03-06) - Initial work; starting virtual machines per wake-on-lan works
#
# Distributed under the terms of the GNU General Public License v3 (https://www.gnu.org/licenses/gpl)
 
 
 
function LOG {
    logger -i "dosthol: ${CMDONLAN} VM ${VMID} (${VMNAME}) (${WHICHVIRT})"
}
 
# check for missing dependencies
for packages in gawk socat xxd; do
    checkbin=$(which ${packages} &>/dev/null)
    [[ ${?} = 1 ]] && echo "Missing program ${packages}, can't continue without it. Exiting." && exit 1
done
 
while PID=$(pidof -x dosthold.sh); do
FNAM=$(mktemp)
 
# socat listens on udp/9, when packet arrives it exits
# gawk magic thanks to <https://stackoverflow.com/questions/31341924/sed-awk-insert-commas-every-nth-character>
socat -u udp-recv:9,readbytes=102 - | xxd -u -p -c 102 | gawk '{$1=$1}1' FPAT='.{2}' OFS=: > ${FNAM}
 
# get header (6*FF / 6*EE)
WOLHEADER=$(cut -b 1-17 ${FNAM})
 
# valid header?
case "${WOLHEADER}" in
    "FF:FF:FF:FF:FF:FF")    CMDONLAN="start" ;;
    "EE:EE:EE:EE:EE:EE")    CMDONLAN="shutdown" ;;
    "DD:DD:DD:DD:DD:DD")    CMDONLAN="stop" ;;
    "CC:CC:CC:CC:CC:CC")    CMDONLAN="suspend" ;;
    "BB:BB:BB:BB:BB:BB")    CMDONLAN="resume" ;;
    "AA:AA:AA:AA:AA:AA")    CMDONLAN="reset" ;;
    "AB:AB:AB:AB:AB:AB")    CMDONLAN="reboot" ;;
esac
 
if ! [ "${CMDONLAN=}" = "" ]; then
    # 16*MAC
    WOLMAC=$(cut -b 19- ${FNAM})
 
    # MAC we're searching for
    MAC=$(cut -b 19-35 ${FNAM})
 
    # 16*identical MAC = MagicPacket ?
    if [ $(echo ${WOLMAC} | grep -o ${MAC} | wc -l) = 16 ]; then
 
    # search pve for MAC addresses
    # gawk magic thanks to <https://stackoverflow.com/questions/245916/best-way-to-extract-mac-address-from-ifconfigs-output>
    PVEMACS=`grep -r "net[0-9]:" /etc/pve/local/ | grep -ioE "([[:xdigit:]]{1,2}:){5}[[:xdigit:]]{1,2}" | grep -io -m1 "${MAC}"`
 
    # matching MAC?
    if [ "${PVEMACS}" = "${MAC}" ]; then
        WHICHVIRT=$(grep -r -m1 "net[0-9]:" /etc/pve/local/ | grep -i "${MAC}" | awk -F '/' '{print $5}')
        WHICHVMID=$(grep -r -m1 "net[0-9]:" /etc/pve/local/ | grep -i "${MAC}" | awk -F '[/:]' '{print $6}')
        VMFILE=$(find /etc/pve/local/ -name ${WHICHVMID})
        VMNAME=$(grep -m1 "name: " ${VMFILE} | awk {'print $2'})
        VMID=$(echo ${WHICHVMID%.conf})
        if [ "${WHICHVIRT}" = "qemu-server" ]; then
        LOG
        qm sendkey ${VMID} ctrl-alt &
        qm ${CMDONLAN} ${VMID} &
        fi
        if [ "${WHICHVIRT}" = "lxc" ] && ! [ "${CMDONLAN}" = "reset" ]; then
        LOG
        pct ${CMDONLAN} ${VMID} &
        fi
    fi
    fi
fi
 
# remove obsolete/invalid socat file
rm ${FNAM}
done

Make it executable

chmod +x /usr/local/bin/dosthold.sh

Create a new file /etc/systemd/system/dosthol.service with the following contents:

[Unit]
Description=dosthol (Do something on LAN)
 
[Service]
ExecStart=/usr/local/bin/dosthold.sh
RestartSec=1
Restart=always
 
[Install]
WantedBy=multi-user.target

Start, enable, status the service:

systemctl enable dosthol.service
systemctl start dosthol.service
systemctl status dosthol.service

Verify

We will use a terminal command to send out a WoL magic packet.

sudo apt install wakeonlan
wakeonlan ${MAC_ADDRESS}

Homelab #8 - Wake on LAN (WoL) Proxmox

Table of Contents

WoL Setup Proxmox Host Machine

In BIOS

In OS

WoL Setup Proxmox Guest Machines

Verify