Modern technologies do not get tired of developing and delighting users. For example, today it has become possible to turn on a personal computer from a distance without any effort. There is such a function (WOL) for a long time, but not all users know how it works and why it is needed.
Wake-on-Lan: what is it?
This protocol is designed to remotely turn on a computer that has a reserve of standby voltage on the motherboard, thanks to which the power supply can be started. Through WOL, the additional ability to wake up from a wireless network is also configured, if the router supports it.
You will need a similar function to perform scheduled OS component updates and backups on computers that are out of the user's physical reach without the ability to turn it on yourself.
Because modern PCs provide power to the motherboard when they are turned off, Wake-up-On-Lan is usually fine when set up properly.
Only two components are important for WOLcomputer: motherboard and network card. The first one must be connected to an ATX-compatible power source, allowing the LAN adapter to view all packets that come to it. If one of them contains a special command containing the MAC address of the network card, it will send a signal to start the PC power supply.
Otherwise, Wake-On-Lan (remote start program) does not require additional utilities to be downloaded: this feature is configured via the BIOS.
The command mentioned above is called Magic Packet. It is he who must receive the network card to activate the start of the computer. It contains the MAC address of the LAN adapter, repeated 16 times, and other required information.
This packet can be sent from the OS, website or router using UDP ports 7 and 9. However, if this function is not needed and the PC can be connected to the mains, it is better to deactivate it, since it negatively affects the battery level.
How to enable WOL
Older computer models, as well as some newer ones, have a Wake-On-Lan setting in the BIOS. To do this, it is worth knowing English at least at the initial level, otherwise the user simply will not find WOL, because today this designation is not used in the basic I/O system.
Usually you should look for something similar in the power management section, for example, lines with the names Wake-Up by PCI device or Power on by Ethernet Card.
However, if the PC is running Linux OS, to run the function, you will need to install the built-in utility Ethtool, which will check WOL support on the network card.
Since Windows 7 supports Wake-On-Lan on a par with older versions, you can also enable the protocol through the user interface of this OS. To do this, through the "Start" you need to find "Computer Management" and enter the "Device Manager" in order to find the network adapter in the list that opens.
Next, by clicking the right mouse button, you need to call its context menu, open "Properties" and go to the "Advanced" tab. In the displayed list, the user must select the Wake on Magic Packet item and set its value to on. You do not need to restart your computer.
To send a pull request, you need to know the MAC address, hostname, subnet mask, and port number to use. Downloading the program for transferring the “magic package” is simple. The web is full of various utilities, as well as websites that perform this function online.
This item is needed only if the PC is turned on via the Internet, and not a local network. This will require a permanent and unique IP address provided to the user by the provider. Otherwise, you will have to rent a static external IP address or use a dynamic DNS client, accessing the equipment through its domain name. An approximate setting is to set a NAT translation rulefor the IP address used to connect to the Network: UDP protocol, ports 7 and 9.
Next, you need to create a broadcast address for the router, which is also needed to send the packet. Then you need to connect to the equipment through a special client and enter the following commands:
- ip arp /user address/ ff:ff:ff:ff:ff:ff;
- system config-save.
Then the router is rebooted and the settings take effect.
TeamViewer - software designed for remote access to a computer, which, in combination with a configured WOL, allows you to turn on the device from a distance with less effort. To do this, you will need to take a few more steps, in addition to those described above: configure the firewall and the utility itself.
When you enter the firewall, select "Inbound Rules" and then "Create Rule". In the window that opens, click on "For the port" and "Next". Then, set the values for UDP ports 7 and 9, allow connection to them (and prohibit its publicity). Finally, all that remains is to give the rule a name and confirm the changes with the Done button.
The first step in setting up TeamViewer is to link your computer to an account. This is required for security purposes as the software is not intended to be misused, therefore the computer must be owned by whoever wants to access it.
Account binding is carried out by entering the e-mail and password from the account in a special dialog box that the user can easily find himself. Onceaccount will be assigned to the PC, you will need to set up Wake-On-Lan via TeamViewer ID. This is useful if the device does not have a public address.
In the network settings of the utility, find the "Incoming connections" item and change its value to "Accept". Then, in the same section, you must select "Configuration", after which a dialog box will appear with the WOL wake-up functions. In "Other TeamViewer applications in your network", the user must enter and add their ID.
How to disable WOL
As soon as the need for Wake-On-Lan disappears, it is better to disable the utility to save battery power and avoid interference on third-party equipment, sometimes occurring when in contact with a computer that has this feature enabled.
To do this, you will need to do the reverse of what is listed in the "How to enable WOL" section of this article. However, before that, you need to go to the properties of the network card and uncheck all the boxes in the "Power Management" tab so that the PC remains de-energized after shutdown and cannot be turned on by third-party demand.
Then, in the "Advanced" section, the user must disable the launch of the device via Magic Packet, and to be sure of the success of the operation, it is worth deactivating WOL in the BIOS settings. This is done in the same branch that was indicated above in the text.
How to check if WOL is working
You can only check the functionality of the utility by experience, being directly next to the PC. This is done using TeamViewer or other third-partyprograms and resources that allow you to send a Magic Packet.
However, there is one not-too-pleasant moment: some devices with Wake-On-Lan configured and enabled via the BIOS network start the power supply on their own without sending and receiving Magic Packet. The reason for this is the slightly increased functionality of Intel and 3COM network cards, which use not only WOL to signal the PC to turn on over the local network. They also use other events: by default, as a rule, several criteria are set at once, on which the awakening depends.
This problem is solved by changing the adapter settings using third-party software. You just need to remove the extra conditions for the function to work correctly.