- Enabling Wake-On-LAN (In Ubuntu 20.10)
- Table of Contents
- Beginning
- Middle
- Ethtool
- Checking the Interface
- Turn It On Temporarily
- Test It Out
- Take Two
- Making It Permanent
- Set It Up
- Enable The Service
- Wake on lan and linux
- Wake on lan and linux
- Ubuntu Documentation
- Enabling WoL in the BIOS
- Using an Integrated NIC
- Using a Non-Integrated NIC
- Enabling WoL in the NIC
- Determining whether the NIC supports WoL
- Enabling WoL in the NIC
- Testing Wake-On-LAN
- Command-line tools
- GTK+ tool
- Configure other operating systems
- Troubleshooting
- External Links
Enabling Wake-On-LAN (In Ubuntu 20.10)
Table of Contents
Note: The systemd configuration here isn’t quite right, but since this post is kind of long and convoluted I made a standalone update about the systemd configuration file in this post.
Beginning
These are my notes on getting Wake-On-LAN working in Ubuntu 20.10. I have a server that I use to run most of the computation on when I use emacs/jupyter but I have it in a corner upstairs and although it’s only a little walk, I find that the fact that I have to stop what I’m doing and go upstairs to push that little button on the front makes me lazy and so it ends up running more than it has to so I thought I’d enable Wake-On-LAN so I can suspend it and wake it up whenever I need to. I’m only going to use suspend (APM S3). When I tried to use hibernate (S4) it ended up shutting down my machine (S5). Interestingly, my BIOS menu has an option to enable waking up from shutdown, but since my disk is encrypted, and I didn’t set up a separate SSH server, I have to go enter the passphrase to unlock the disk before the operating system can boot up, so it kind of defeats its own purpose.
Middle
Ethtool
The command I used to set up Wake-On-LAN on the remote machine is called ethtool. It’s in the Ubuntu repositories but wasn’t installed on my machine so I had to add it.
Checking the Interface
From what I’ve read, not all ethernet interfaces support Wake-On-LAN (although I’ve never seen one that doesn’t) so a quick check might be useful. First, find the name of your ethernet interface.
My machine shows four interfaces so I’ll just show the output for the interface I’m interested in rather than the whole output for the command.
Ethtool uses the name of the interface, in this case it’s enp4s0 , so we’ll need to note that. Additionally, the machine that I used to wake up the machine needs the MAC address ( 38:d5:47:79:ab:0b ) so it’d be useful to write that down someplace. I’m waking it up from the LAN so the IP address isn’t so important, and to be able to SSH into it I need to know it anyway, so it’s really those two pieces of information that I need. Now to check if it supports Wake-On-LAN.
Ethtool will give you some information if you don’t run it as root but for Wake-On-LAN you need to run it as root. The important lines in the output is near the bottom and it looks something like this if it supports Wake-On-LAN.
The man-page for ethtool tell you what that cryptic pumbg means — the letters are different options that this interface supports for Wake-On-LAN. In this case they are:
| Option | Description |
|---|---|
| p | Wake on PHY activity |
| u | Wake on unicast messages |
| m | Wake on multicast messages |
| b | Wake on broadcast messages |
| g | Wake on MagicPacket messages |
There’s an additional option which is what the interface was set on – d – as you can see in the last line of the output. This means Disable (wake on nothing). This option clears all previous options. I don’t have many devices on my network, so I don’t know that there’s a lot of broadcasts, multicasts, etc. that would be waking it up all the time, but since one feature of Wake-On-LAN is that it only wakes the machine when it gets the «Magic Packet», only the g and d options matter. Now that I knew it was supported, it was time to try it out.
Turn It On Temporarily
The ethtool will turn on Wake-On-LAN, but (supposedly) everytime you reboot the machine it will reset to disabled. I haven’t really tested this out, but I’ll document how to make it permanent later, anyway.
So, as you might guess, we changed the Wake-On-LAN setting to listen for MagicPacket messages. You can check using the ethtool again.
The Wake-on line should have changed to:
Now to suspend the machine so we can test it out.
Test It Out
Now, on my local machine I needed to install wakeonlan. There’s a surprising number of programs to send the Magic Packet, but this just happened to be the one I used.
The default way to use wakeonlan is apparently to just pass it the MAC address of the computer to wake up, and it will send the Magic Packet out as a broadcast, so that’s what I did.
And then I pinged the machine and I waited. And I waited. And I waited… Eventually I went upstairs and saw that it was still sleeping so I pushed the power button to wake it up and went back downstairs.
Take Two
Something wasn’t right so I SSHd into the server and started up tcpdump to see if the packets were going through.
Which gave me this output:
And then I sent the Magic Packet again.
…And nothing happened. For some reason the packets weren’t getting picked up by the machine. Luckily, wakeonlan lets you pass in an IP address as an option. The man page recommends using a broadcast address, but I have the IP addresses of my machines on the LAN reserved on my router/access-point so I just passed in the full address (I did try the LAN broadcast and it worked too).
I have my machine’s IP address aliased in my /etc/hosts file so erebus is just an alias for the machine’s IP address. The subnet broadcast version looked like this.
The output from tcpdump for the first packet looked like this.
So, something was different. I suspended the machine again and sent the Magic Packet and this time it worked. Go figure.
Making It Permanent
Set It Up
The reasons that I said earlier that the Wake-On-LAN setting «supposedly» is temporary is that:
- I haven’t really re-booted that machine to test it out (I have rebooted, but I haven’t disable the systemd service that I’m documenting here).
- The machine that I’m typing this on had Wake-On-LAN enabled and it doesn’t have a systemd service enabled.
But, really, I don’t remember even enabling Wake-On-LAN on this machine so maybe it just was the default and I didn’t realise it… another thing I should look into one of these days. Anyway, to make a service that always enables Wake-On-LAN the first step is to find the path to ethertool .
In my case the path was /sbin/ethtool , so once you know this you can create a file at /etc/systemd/system/wol.service (I think you can use another systemd sub-folder, and you can name the file anything you want, within reason, but this one seems to work well enough). In this file you put settings that look something like this:
The only thing specific to my machine is enp4s0 , the name of the ethernet interface, although it’s possible that the path to the ethtool executable might be different too… but it should be the same on Ubuntu 20.10, anyway.
Enable The Service
To enable it you can do this:
Where wol.service is the name of the file you created with the settings. You can check its status if you want.
So, that’s how I got one machine working with Wake-On-LAN. Hopefully I won’t have to look so hard the next time. Here’s the pages that I stole this from.
- TechRepublic on using ethtool and setting up a systemd service for this (don’t use the systemd file here, though).
- Stack Overflow on how to suspend and hibernate from the command-line
- Stack Overflow on what the difference is between suspend and hibernate
- Stack Overflow on using tcpdump to look for the Magic Packets on the remote machine
- Stack Overflow on editing remote files as root with emacs (not documented here, but maybe later)
- Stack Overflow on editing a local file as root with emacs (not used here, but I can never remember the syntax)
Источник
Wake on lan and linux
опять перейдёт в состояние «d» и, если вам нужно, добавьте приведённую выше
команду куда-нибудь в /etc/rc.local.
Это может не работать (или не сработать второй раз), если выполнялся сброс (переинициализации) карты (в том числе — на ноутбуках после «сна»).
Лучше это делать из:
— Ubuntu/Ddebian: /etc/network/interfaces в post-up / pre-down
— AltLinux — в /etc/net/ifaces/ethX/ifup-post
— в других — в соотв. местах, выполняемых _каждый раз_ после инициализации устройства или перед его отключением.
| 1.4 , Р ( ? ), 12:58, 21/12/2010 [ответить] | + / – |
| хочу через интернет. ))) | |
| 1.6 , Alex ( ?? ), 01:17, 27/12/2010 [ответить] | + / – |
| > девятый порт, помеченный в /etc/services как discard, что означает то, что > пакет с этого порта отправить не получится Бред, это просто название протокола, RFC863. | |
| 1.7 , sam ( ?? ), 17:23, 29/12/2010 [ответить] | + / – |
 Прошу добавить в статью важный момент, я сам полчаса мучался пока не дошло до меня посмотреть куда уходят пакеты tcpdump-ом Если на компьютере несколько сетевых карт обязательно нужно указать в параметр -i адрес Например, если нужно разбудить комп с адресом 192.168.2.34 в сети 192.168.2.0/24 то можно так и указать например широковещательный адрес сети Источник Wake on lan and linux
Как настроить Wake On Lan в Linux-01 Всем привет сегодня расскажу как настроить Wake On Lan в Linux. WakeOnLan (WOL) — это технология позволяющая включить компьютер, методом отправки на него специального пакета данных, называемыми Magic Packet. Принцип работы этой технологии таков, что при выключении компьютера он переходит в дежурный режим и переводит сетевую карту в режим пониженного потребления, просматривая все поступающие пакеты из сети. Если сетевой адаптер обнаружит Magic Packet, он выдаст сигнал на включение компьютера. Примечание: для использования данной технологии необходима поддержка данной функции (технологии) сетевым адаптером, почти все современные сетевые адаптеры поддерживают данную технологию. В данном посте мы рассмотрим настройку данной функции на примере ОС Linux. 1. В первую очередь мы просмотрим список наших сетевых интерфейсов используя утилиту ethtool: В ответ получим список наших используемых сетевых интерфейсов (в моём случае он 1): eth0 Link encap:Ethernet HWaddr 6c:62:6d:f0:ce:b4 Нам необходим интерфейс который имеет доступ к внешней сети (в моём случае eth0). Теперь проверим поддерживает ли сетевой адаптер данную технологию и настроим её используя утилиту ethtool. Устанавливаем её: и запустим её, для просмотра информации о сетевом интерфейсе: В ответ мы получим всю информацию о нашем сетевом интерфейсе: Settings for eth0: Где Supports Wake-on: pg — означает что наш сетевой интерфейс поддерживает технологию Wake On Lan, Wake-on: d — но она отключена. Wake On Lan можно включить вручную 1 командой, но при каждой перезагрузке нашей машины он будет деактивироватся, для этого мы создадим и будем использовать специальный скрипт. Добавляем в скрипт строки: Даём права скрипту: Создаём символическую ссылку и делаем наш скрипт исполняемым: Проверяем что всё нормально вводим команду: Если ничего в ответ не получили, значит всё хорошо и можно проверить на практике. Вот так вот просто настроить Wake On Lan в Linux Источник Ubuntu DocumentationThis page explains how to enable use of Wake-on-LAN (WoL) in systems that have Ubuntu installed. Wake-on-LAN enables users to turn on a computer across a network from another network device. It can be very useful in situations where computers are not all next to each other or there are a lot of machines. WoL works by sending a packet of data called a Magic Packet™ to the target machine. When the packet is received, the target machine’s network device (Network Interface Controller or NIC) wakes-up the rest of the machine. In order to use WoL it must be supported and enabled as necessary in the BIOS, NIC and other network hardware (routers, switches etc). You may also need to configure some software if things don’t work out-of-the-box. Enabling WoL in the BIOSThis section may differ depending on whether or not you have a NIC integrated into your motherboard. Using an Integrated NICTo enable WoL in the BIOS, enter the BIOS setup and look for something called «Wake up on PCI event», «Wake up on LAN» or similar. Change it so that it is enabled. Save your settings and reboot. Using a Non-Integrated NICIf your NIC is not integrated into your motherboard, you will still have to configure your BIOS to allow devices to wake up your computer. Boot your computer and enter the BIOS settings menu. In one of the sub-menus there will hopefully be the option to allow USB and/or PCI devices to wake-up the computer. Enable the setting that is appropriate for your NIC. Save your settings and reboot. PCI NICs sometimes require a cable connection to the power supply in order to stay awake when the computer is off/asleep. Check your manual to see if yours does and install if necessary. Enabling WoL in the NICDetermining whether the NIC supports WoLFirst, determine which NIC will be used, and then check whether it supports the Magic Packet™ using where is the device name of your NIC, e.g. eth0. This command will output some information about your the capabilities of your NIC. If this output contains a line similar to the following: where contains the letter g, the NIC should support the WoL Magic Packet™ method (for the other letters look at man ethtool). Enabling WoL in the NICTo check whether WoL is enabled in the NIC, one could use If contains g and not d, then Magic Packet™ is enabled. However, if does contain d, WoL needs to be enabled by running the following command: On most systems, issuing this command is required after each boot. If the system’s networking is configured via ifupdown, then it is easy to add the line up ethtool -s wol g below the interface’s configuration stanza in /etc/network/interfaces. For example: This will ensure that WoL is enabled in the NIC on each boot. Fore more information see the interfaces manual. Testing Wake-On-LANTest WoL by powering off the system and trying to send it the magic packet using: Command-line toolsGTK+ toolConfigure other operating systemsIf the system dual-boots with other operating systems, they should be configured to also enable or, at least, not disable WoL in the NIC. This is beyond the scope of this document but here’s a starting point for Microsoft’s OS’s. TroubleshootingIf WoL is not working as expected, there are a number of lines of investigation to follow:
WakeOnLan (последним исправлял пользователь g1orgosp 2015-08-31 14:29:10) The material on this wiki is available under a free license, see Copyright / License for details Источник | |
