Written 4 Sep 2026. This is a how-to, not a product card.

Wake the computer from the house network

Soft-off is fine overnight. Wake the old PC from a laptop or phone on the house network so SSH and Pi-hole come back. You don't need a smart plug for this.

You shut it down on purpose, or the power button put it in soft-off. The wall outlet is still live. A short magic packet on the house network can turn it back on. That trick is Wake-on-LAN. Prefer a cable into the router. Wi-Fi wake is flaky on most old machines. Haven't found its address yet? Find it on the house network. If you only need it to stay awake with the lid closed, that is don't let the old laptop sleep, not this note.

Skip until soft-off is the problem

If the computer answers ping already, you don't need Wake-on-LAN tonight. If ads are back and you are not sure it is even powered, start with is the computer still on?. If you yanked the power strip, Wake-on-LAN cannot help until power is back. Don't buy a smart plug as the first fix.

What this is

Soft-off means the computer looks off, but the network chip still sips a little power and listens for a special packet. That packet is a Wake-on-LAN magic packet. Your laptop or phone on the same house network sends it. The computer powers on, boots, and then SSH and Pi-hole come back the usual way. Hard power-off (strip unplugged, PSU switch flipped) kills the listener. Guest Wi-Fi that isolates devices often blocks the packet too.

What you need

A cable from the computer to the router or switch when you can. The hardware address (MAC) of that ethernet port. Soft-off, not a dead outlet. Write the MAC down once while the machine is still on. On Ubuntu Server or Debian:

ip link show

Find the wired interface (often enp* or eth0). The link/ether line is the MAC, six pairs like aa:bb:cc:dd:ee:ff. A sticker on the OptiPlex case sometimes has the same number. Need a slower walk through that address? See see its hardware address.

Turn it on in the BIOS

Reboot. Open the one-time setup menu (Dell often F2, HP Esc then F10, Lenovo F1 or Enter then F1). Look for Wake on LAN, Wake on LAN from S5, or Deep Sleep / ErP. Turn Wake on LAN on. Turn deep sleep / ErP off if that option exists, or the NIC sleeps too hard to listen. Save and exit. You only dig here once. Skip a full BIOS tour for every other setting tonight.

Turn it on in Linux

While the computer is still awake, install the small tool that talks to the NIC:

sudo apt update && sudo apt install -y ethtool

Swap enp3s0 for your wired interface from ip link:

sudo ethtool -s enp3s0 wol g

Check that it stuck for this boot:

ethtool enp3s0 | grep -i wake

You want Wake-on: g. If the line says d or refuses the change, the BIOS switch is still off, or that NIC cannot do Wake-on-LAN.

Make it survive a reboot

ethtool -s … wol g often resets after reboot. A tiny oneshot service puts it back. Create the unit:

sudo tee /etc/systemd/system/wol.service <<'EOF' [Unit] Description=Enable Wake-on-LAN on the wired NIC After=network-online.target Wants=network-online.target [Service] Type=oneshot ExecStart=/sbin/ethtool -s enp3s0 wol g [Install] WantedBy=multi-user.target EOF

Swap the interface name inside that file if yours is not enp3s0. Then:

sudo systemctl daemon-reload

sudo systemctl enable --now wol.service

Reboot once when you can. Run the ethtool … | grep -i wake check again. You want g after the reboot too.

Shut down the polite way

Wake-on-LAN needs a clean soft-off. From the couch:

sudo shutdown -h now

That is shut down without yanking the plug. Wait until the fans stop. Leave the wall power connected.

Wake it from a laptop

On another computer on the house network (not Guest Wi-Fi), install a sender. On Ubuntu or Debian:

sudo apt install -y wakeonlan

Then send the packet with the MAC you wrote down:

wakeonlan aa:bb:cc:dd:ee:ff

On a Mac with Homebrew you can use wakeonlan the same way, or a short Python one-liner if you already have Python. On Windows, a small Wake-on-LAN utility that asks for the MAC is enough. Stay on the house network. Don't open a port on the router for this.

Wake it from a phone

Any simple Wake-on-LAN app that asks for the MAC works on house Wi-Fi. Type the same six pairs. Send once. Wait a minute for boot, then open SSH or check that ads are gone again. Skip apps that want an account or a cloud relay for a first test.

Check it worked

After you send the packet, wait for the POST beep or the fan spin. From the laptop:

ping -c 3 192.168.1.50

Swap in the computer's number. When ping answers, SSH from the couch. If ping never answers, recheck cable, BIOS Wake on LAN, Wake-on: g, and that the machine is soft-off rather than unplugged. A laptop on battery-only Wi-Fi often cannot wake; plug ethernet when you can.

What this is not

This is not a reason to buy a smart plug, a KVM over IP, or a new mini PC. It is not remote wake from a coffee shop. The magic packet stays on the house network. It is also not the fix for a laptop that only slept with the lid closed. That is still don't let the old laptop sleep.

What next

Once it wakes, confirm the house jobs still run: after a reboot, check the computer still does its jobs. If the address moves after power cycles, reserve it or set a fixed one: keep the computer on the same address on common routers, or give the computer a fixed address when the router won't. Prefer a cable over Wi-Fi for the listener: a cable beats Wi-Fi for the old PC. If you shut it down often, keep the polite shutdown habit: shut down without yanking the plug.

Skip

• Skip a smart plug as the first wake tool.
• Skip opening Wake-on-LAN through the router to the internet.
• Skip Wi-Fi wake on day one when a cable is available.
• Skip this if the computer stays on all week and never soft-offs.
• Skip a KVM over IP for a first OptiPlex in the closet.