Wake On Lan B450 Tomahawk Arch Linux

So you’ve got an MSI B450 Tomahawk, Arch Linux running like a dream, and a sudden urge to wake your computer from across the house. Welcome to Wake On Lan, the magic trick that turns a tiny network packet into a power button. It’s part sorcery, part BIOS scavenger hunt, and entirely satisfying once it works.

Here’s the good news: the B450 Tomahawk absolutely supports Wake On Lan. The bad news? It won’t do it until you nudge a few settings in the right direction. Think of it as teaching your motherboard to perk up when someone whispers its MAC address.

What Wake On Lan actually does

Wake On Lan, or WOL, sends a special “magic packet” to your network card while the rest of the PC is asleep or powered off. That packet includes your machine’s MAC address repeated a bunch of times, like a very nerdy chant. If the network card is still sipping standby power, it hears the chant and tells the motherboard to boot.

For this to work, three things need to line up. Your BIOS must allow PCI-E wake events, your Linux network driver must keep the card armed, and the magic packet must actually reach the card. Miss one, and your PC stays stubbornly comatose.

First, poke around your BIOS

Reboot the Tomahawk and mash Delete like you’re trying to win a rhythm game. Once inside the MSI BIOS, switch to Advanced mode if you’re stuck in the simplified view. The exact menus can shift with firmware versions, but the usual path is Settings > Advanced > Power Management Setup.

MSI B450 Tomahawk settings to hunt down

Look for ErP Ready and set it to Disabled. When ErP is enabled, the board cuts almost all standby power, which is great for the planet and terrible for WOL. Your network card needs a little juice to listen for that magic packet.

Next, find Resume By PCI-E Device and enable it. This is the green light that lets a PCI-E device, including your onboard Realtek NIC, wake the system. Some BIOS versions also show Wake Up Event By; setting it to OS often plays nicer with Linux, though BIOS can work too.

Save your changes and boot into Arch. If you changed nothing and WOL still fails, come back here. The BIOS is usually the bouncer refusing entry.

Arch Linux: where the real fun begins

Open a terminal and install the tools you’ll need. Run sudo pacman -S ethtool wakeonlan and let Pacman do its thing. Yes, you need ethtool to configure the card, and wakeonlan to send test packets later.

Specification B450 TOMAHAWK | MSI France

Find your network interface name with ip link. It might be something like enp4s0, enp5s0, or another cryptic string. Write it down, because you’ll type it more than you’d like.

Now check what your card supports. Run sudo ethtool enp4s0 and look for the Wake-on line.

If it says d, WOL is disabled. If it says g, you’re already golden. The supported modes often look like pumbg; the g means “magic packet,” which is exactly what we want.

Arm the card with sudo ethtool -s enp4s0 wol g. That command is the equivalent of taping a “wake me up” sign to your NIC. Unplug the Ethernet cable and plug it back in? Recheck with ethtool, because some drivers reset the setting.

Make it stick with systemd

Running that command manually is fun exactly once. To make it survive reboots, create a small systemd service. Use sudo nano /etc/systemd/system/wol.service and paste in a unit that runs /usr/bin/ethtool -s enp4s0 wol g after the network is online.

Then run sudo systemctl daemon-reload, followed by sudo systemctl enable --now wol.service. Check its mood with systemctl status wol.service. If it’s green and happy, your card should be armed every boot.

Some folks prefer a udev rule instead, which is fancy and effective. But for most B450 Tomahawk owners on Arch, a simple systemd service is less headache and more readable. Keep it boring; boring is reliable.

MSI B450 TOMAHAWK MAX II AM4 Ryzen ATX Motherboard 4xDDR4 5xPCI-e 1xM.2

Testing: the dramatic moment

Shut the machine down completely, not just suspend. From another device on the same network, run wakeonlan YOUR:MAC:ADDRESS. You can find the MAC with ip link show enp4s0 before shutting down.

If the fans spin up and the motherboard beeps to life, do a little victory dance. If nothing happens, don’t panic. Double-check that the Ethernet cable is connected, the router isn’t isolating clients, and you’re on the same subnet.

Also remember: WOL over the internet requires port forwarding or a VPN, and it’s usually safer with a VPN. Magic packets don’t like being shouted across the open internet. Keep them on your LAN unless you know what you’re doing.

If it refuses to wake up

First, verify the BIOS settings again, especially ErP Ready and Resume By PCI-E Device. A firmware update might have reset them, because motherboards enjoy chaos. Second, confirm with ethtool that Wake-on: g is still set after a full shutdown.

Third, try a different magic packet sender or check your router’s ARP table. Sometimes the packet is sent to the wrong broadcast address, like a party invitation delivered to the wrong house. Finally, test with the PC in suspend instead of full shutdown; if suspend works but shutdown doesn’t, BIOS power settings are the culprit.

Final happy thoughts

Once Wake On Lan works on your B450 Tomahawk with Arch Linux, it feels like you’ve unlocked a secret cheat code. Your PC becomes a loyal digital pet that comes running when called, no matter how far away you are. And honestly, that’s a pretty delightful thing to have in your corner.

So go forth, tweak those BIOS switches, arm that Realtek card, and enjoy the small miracle of remote booting. May your magic packets always find their target, and may your computer never ignore you again. Happy waking!