Does Wake-on-LAN (WoL) depend on the motherboard or the network card

biosmotherboardnetwork-adapterwake-on-lan

This question was spurred by discovering the Acer M670G seems not have an Wake-on-LAN (WoL) settings in the BIOS and in general, wondering whether WoL is controlled by the BIOS/NIC or the OS.

One of my colleagues, “A” was discussing on the Wake-on-LAN (WoL) functionality and mention that WOL depends on the motherboard and the BIOS settings.

Another colleague, “B” begs to differ. Colleague “B” think that if you have purchased and plugged in a PCI network card, the WoL functionality will then depend on the operating system as well as if the new internal PCI network card support WoL or not.

So should one say that the WoL functionality depends on the motherboard and the BIOS if the network card is embedded into the motherboard?

Also, can one assume that if one plugs in an internal PCI Network card onto the motherboard—regardless if the motherboard has existing embedded network card or not—the WoL functionality will now depend on the installed operating system and whether the network card has WoL functionality?

Best Answer

Colleague “A” is 100% correct: Wake-on-LAN (WoL) functionality dependent on the motherboard and related BIOS settings. The NIC should be able to support WoL and the BIOS needs to be able to make sense of the NIC saying, “Hey! This is your NIC and my WoL has been triggered! Do you care do do something with this info, motherboard?”

As explained very clearly on Wikipedia, Wake-on-LAN comes from the NIC’s firmware and is paid attention to by motherboards that respect WOL; bold emphasis is mine:

Wake-on-LAN support is implemented on the motherboard of a computer and the network interface (firmware), and is consequently not dependent on the operating system running on the hardware. Some operating systems can control Wake-on-LAN behaviour via NIC drivers. With older motherboards, if the network interface is a plug-in card rather than being integrated into the motherboard, the card may need to be connected to the motherboard by an additional cable. Motherboards with an embedded Ethernet controller which supports Wake-on-LAN do not need a cable. The power supply must meet ATX 2.01 specifications.

And with more detail of how the BIOS plays into the whole setup; again bold emphasis is mine:

Wake-on-LAN usually needs to be enabled in the Power Management section of a PC motherboard's BIOS setup utility, although on some systems, such as Apple computers, it is enabled by default. On older systems the bios setting may be referred to as "WOL", on newer systems supporting PCI version 2.2, it may be referred to as "PME" (Power Management Events, which include WOL). It may also be necessary to configure the computer to reserve standby power for the network card when the system is shut down.

And even more details from “How-To Geek Explains: What is Wake-on-LAN and How Do I Enable It?”; yet again bold emphasis is mine:

WoL is dependent on two things: your motherboard and your network card. Your motherboard must be hooked up to an ATX-compatible power supply, as most computers in the past decade or so are. Your Ethernet or wireless card must also support this functionality. Because it is set either through the BIOS or through your NIC’s firmware, you don’t need specific software to enable it. Support for WoL is pretty universal nowadays, even when it’s not advertised as a feature, so if you have a computer built in the past decade or so you’re covered.

And on many modern systems, there is no explicit WoL setting in the BIOS with the functionality either given a different name or buried under other power settings as explained in this Lifehacker post:

To access your BIOS, restart your computer and press and hold the Delete key (or whatever key your BIOS prompts you to hold) to enter the BIOS setup. Once you're in the BIOS, head to the Power management section and look for a Wake-on-LAN setting. If you find one, go ahead and make sure it's enabled, then save and exit your BIOS and start up your computer. Not all BIOS will have a straight-up Wake-on-LAN option, and on some boards you may have to enable a "Power On By PCI Devices" setting. It varies from board to board, so a little trial and error may be in order.

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