How do you remotely power on a home computer with a router? Wake on LAN setup for the entire process, I stepped on it for three nights

first figure out what kind of shutdown method it is—not every way can be woken up

. Last month, I went on a business trip to Hangzhou, and one night a client suddenly asked for a quotation. The document was in the desktop computer in the study. If the computer is turned off, Remote Desktop definitely can't connect—no matter how powerful Remote Desktop software is, the machine must be turned on first. At that time, I was rummaging through my phone in the hotel and finally remembered an old thing: Wake on LAN, network wake-up. When the network card is "powered off," it actually doesn't completely lose power; it is still listening intently to LAN broadcasts, and receiving a packet in a specific format notifies the motherboard to power on. This package is called the Magic Package, and its content is simple and direct: six bytes of FF, followed by sixteen iterations of the target network card's MAC address, totaling 102 bytes.

But there's a big premise: there are several ways to "shut down" a computer: if the screen goes black, it's just sleep, and the memory is still powered—this is the best way to wake you up; Sleep mode is to store memory on the hard drive and then cut off the power; A real shutdown means even the motherboard's standby circuit has only a small amount of power left. Whether it can be woken up depends on whether the network card still receives that bit of power after the power is cut off. This is the BIOS setup that will handle this later. For those three nights, I spent more than half the time on the mystical question, "Why do I wake up the first time, but never the second time?" The answer was hidden in these details.

also set expectations right: wake-up is just powering on. After booting up, you still have to rely on remote desktop or ToDesk software to get things done. I've previously written about how to get home via VPN, all three routes are in this article. This article will focus only on "waking up the machine."

two switches on the computer side, the one in BIOS that is most likely to leak

has to pass through two tests; missing one is pointless. The first step is in BIOS. After restarting, press Del (ASUS motherboards use this key; most other brands use F2), then go to APM Configuration under the Advanced menu. Some motherboards call it Power Management. Go in and select two options: ErP Ready, change it to Disabled; Wake on LAN or Wake on PCI-E, change to Enabled. ErP is an EU energy-saving standard. When you turn it on, the power on the network card will be cut off when the machine shuts down, and if the network card falls asleep, you can't hear the broadcast. Even if you send the magic package ten thousand times, it won't help. These two default values vary by manufacturer. My ASUS motherboard has ErP off by default, but I still recommend you go in and see it for yourself, because the next mishap will be here.

second lane in Windows. In Device Manager, find Network Adapter, right-click Properties, then the Power Management tab, and check "Allow this device to wake up the computer"; Then switch to the Advanced tab and set "Magic Data Packet Wake-up" to enabled. And there's another trick: in the Control Panel power options, it's best to uncheck the 'Enable Quick Start' check. When the fast boot is on, Windows' "shutdown" is actually a hybrid hibernation, leaving the network card half-dead. Some machines happen to wake up, while others don't. In my tests, it's the latter. After canceling Quick Start, the startup takes a bit longer for a few seconds, but in exchange for the wake-up stability value.

these two checkpoints are set, first test it on the intranet: try sending a magic bag to another device at home. Install a small app like Wake On Lan on your phone. Search for this name in the store and you'll find a bunch. Enter your desktop's MAC address, then click Send. You can check the MAC address in the network card attribute details, or look for the IP address in the router's backend device list. How to view the status page I wrote about in my previous article. The machine buzzed and started spinning, and the first level was considered passed.

router side: buttons are convenient, no buttons are outsourced

router side has two flaws. My colleague Xiao Zhou's family uses an ASUS router. Lucky: in the system tools on the left side of the backend, there's a 'Wake-up to Network' page. Select the device from the list and click it, and the machine wakes up without needing any commands. This feature has a prerequisite: the awakened computer must manually bind the IP and MAC in the DHCP server, otherwise the list won't recognize it. The binding steps are the same as giving the printer a fixed address, just follow this article

My main router is the Xiaomi AX3000T. In the background, I flipped from common settings to advanced settings, flipping through everything, but there was no wake-up function page. Xiaomi's official firmware is just like that—accept it. Fortunately, there is more than one path: as long as you have a device at home that has been running year-round, anyone can contract it. My method is to enter Feiniu NAS via SSH, type a wakeonlan with MAC address, press Enter, and the study room will wake up as usual. If you don't have a NAS, hang an old phone or Raspberry Pi under the router, or even have a family member install an app on their phone before heading out—these are all options.

the internal network is awakened to this stage. But the real challenge in business trip scenarios is the next step: when you're not at home, how do you get your magic bag in through foreign networks?

people are on foreign websites, how do you get a magic bag into your home

Awakening from an external site basically means three thresholds, passing through one by one. First, your broadband must have public IPv4. A router's WAN port IP starting with 100.64 indicates the operator's intranet, and packets have nowhere to be delivered. I've written specifically about how to check and ask the carrier for it, the three-step method here. Second, public IPs can drift. My phone drifted from 117.136 to 111.72, so you need to set up DDNS, so the router or NAS will regularly report the current IP to the domain. How to configure it on the router side is explained in great detail this article is very detailed.

the third step is port forwarding, which hides the most common pitfalls in all online tutorials. The Magic Pack is a UDP package, with the preferred port 9. You may have seen tutorials saying to forward UDP 9 to the broadcast address 192.168.1.255—but I advise you not to try. I tried, and AX3000T's forwarding rules don't allow addresses ending in .255. If you force it in, the packet will be silently discarded. Most home routers do not support forwarding to a directional broadcast address, but this is not a problem with your router.

main route is unicast: bind the desktop to a static IP in the router, such as 192.168.1.50, then forward UDP external port 9 to port 9 of 192.168.1.50. Here's another chain detail—when the computer is turned off, it doesn't respond to ARP, the router can't find the MAC corresponding to that IP, and the packet is thrown away when it comes close. Therefore, static binding should be done in the router's IP and MAC binding, so that this record is always kept in the ARP table. I've written a more detailed article about the general operations for port forwarding, everything from filling out to verification is inside. On the mobile app side, remember to change the port from default 7 to 9, enter your DDNS domain for the broadcast address, and for MAC, enter the desktop network card address. Use mobile data to send (testing via home WiFi is cheating, and the package has never left the house).

I messed up three times, all on the details

the first time was the most infuriating. The night before the hotel tested, I successfully tested it, then the next day I sent it out, but it never woke up, spinning the remote desktop in circles forever. After checking at home, I found that Windows Auto updated the network card driver by one version, and after the upgrade, the 'Allow this device to wake up the computer' check disappeared and was quietly removed. Since then, whenever I upgrade the network card driver, I always redo both checks, and this is no problem.

second time, after a night of typhoon power outages, I couldn't wake up no matter what. When you boot up and check the BIOS, ErP Ready automatically returns to Enabled—if the motherboard is out for a long time or the motherboard battery ages, BIOS settings will reset to default. When suddenly it fails, this one comes to mind first. The third time was the previously mentioned .255 broadcast address. According to a certain tutorial, the packet was sent out and disappeared without a trace, and there wasn't a single splash in the router logs. Switching to unicast with static binding immediately worked through.

with two more accounts to settle at the end. A timeline: sending from the phone to the remote home screen can connect. In my tests, it stays stable for around 35 seconds. The main part is boot self-check and system entry, so the wait was worth it. A bill on electricity bills: After turning off the ERP, the network card stays powered year-round, and the desktop standby power consumption rises from less than 1 watt to just over 2 watts. Over ten kWh a year, a few yuan is a matter worth a few yuan. Choosing convenience with your eyes closed is better than convenience. I measured the exact meter numbers using the metering socket, the account is in this article.

who is worth the trouble? Give an order at the end

This feature isn't needed by everyone. If you often need to turn on your computer to get files when you're out, have a desktop at home with files running, or need to go back to work remotely, it's worth getting a setup once—once you've done it, it's basically a one-time solution. If the computer is usually left on and not turned off, there's no need; If you only have a laptop at home and sleep with the lid closed, it's not very meaningful—laptop support for wake-up from external networks is inconsistent, so don't stick to this rigid formula.

follow this sequence of actions, don't skip steps :

Step
• : First, bind the desktop to a static IP in the router and record the MAC address
• Step two: In the BIOS, change ErP to Disabled and Wake on LAN Enabled
• Step three, check both Windows network card properties and disable Fast Boot
• Step four: Use the mobile app to send magic packages to the internal network, verify connectivity
• Step five: Pair with DDNS, use the router to forward UDP 9 to the unicast of that machine IP
• Step six: When the person goes to the external network, pick up the data and send it again, all connected

only after the sixth step is the real match complete. If one day you suddenly can't wake up, don't rush to question your life. Look back at that symptom chart—it's probably the same old tricks from a few old places.