How to set the router to automatically remind new devices when connecting to WiFi? Internet surfers can't wait for this notification, so I figured out the switch positions of the five backends.

Last month, my cousin came to stay at my house for a week. When she left, she said casually, "I have saved your WiFi, and I will connect directly next time." She means well, but my back feels a little cold: I never told her the password. She scanned the QR code I posted on the entrance during the Chinese New Year. The QR code has been torn off a long time ago, and the password has not been changed in three years. Who knows how many times it has been scanned in the meantime.

That night, I didn’t rush to change my password. I did something more useful first.: Turn on the "Automatic reminder for new device connection" on the router. This switch is hidden in the nooks and crannies of various backends and apps, and many people don’t even know it exists. After turning it on, as soon as any unfamiliar device connects to the home WiFi, a notification pops up on the phone immediately, which is ten times easier than looking through the device list to catch the thief afterwards. I checked through several routers at home and those at my parents’ house. The locations of the five routers are all different, and the pitfalls are also different. Let’s talk about them one by one.

Let’s first talk about how this reminder works. Don’t expect it to stop people.

Various companies have different names for this function. Xiaomi calls it "New Device Reminder", TP-LINK's router App is under "Message Push", ASUS Router App calls it "Real-time Network Notification", and Mercury and Tenda's public version firmware generally reads "New Device Access Reminder". No matter how the name changes, the principle is the same: The router keeps an eye on the DHCP allocation record. Once a new MAC address comes to request an IP, it will push a notification to your bound mobile app. Click on it to jump directly to the device details page, where you can see the device name, MAC and the IP assigned at that time.

Note that it says "reminder" here, not "interception". Equipment at this time Already connected , already in your network. So don't think of it as a security door, it's a camera at the door - telling you who has been there, whether to stop you or not is another matter. If you want to stop it, you can rely on the whitelist. I'm here Router blacklists and kicks devices I wrote about the differences between the three levels in that article, so I won’t repeat them here.

There is another premise: 90% of people fail at the first step.: The reminder is pushed through the App. You must first bind the router to the brand App, log in to your account, and then enable system-level notification permissions for the App. If one of the three is missing, the notification will lie in the App and will not appear. The Xiaomi router at my parents' house was tied up, and the notification permission was accidentally clicked "not allowed" when I installed the app. It was equivalent to two years of use in vain.

Find the switch positions of the five backends.

I happen to have five machines of different brands on hand. I copied the records from that night when I was flipping through the menu.:

The details of each company are slightly different. Xiaomi's switch is off by default and is hidden in the second-layer menu of the "Security Center". The big buttons on the Mijia App homepage are not visible at all. ； TP-LINK's is called "Device Access Notification", which is enabled by default, but the notification is only pushed to the App message bar and does not enter the system notification center. You have to click "Sync to System Notification" again.」 ； The Asus one is the most practical. You can choose to push notifications or send emails, which makes emails more stable when you are away from home.

Mercury and Tenda are brothers of the public version of the firmware, and their locations are almost the same. However, Tenda has it in the web background, but Mercury's old D191G cannot be found in the web background. In the end, it was opened from the App. So if you can’t find it, don’t hack the web backend. It’s often faster to install an official App. Also, if the webpage is open in the background, remember to check if there is "Save and take effect". I once thought it was enabled, but when I went back to test, half of the notifications did not come. When I went in, I saw that the switch was still gray.

iPhone users should do this step first, otherwise it will be in vain.

I’ll single out the iPhone here because it’s the deepest pit. Apple strictly controls background push notifications. If a brand router app is not opened for a long time, the system will freeze it in the background. Notifications are forwarded by the manufacturer's server. On the iPhone, notifications are often delayed for more than ten minutes or even not received at all. I tried it on my dad's iPhone 12. When a new device was plugged into the Mercury router, the notification popped up six minutes later. People who were surfing the Internet had already entered their passwords and started watching videos.

There are three steps to cure this: Settings→Notifications→Find the corresponding App→Allow notifications, and select "Lock Screen" and "Banner" for the notification style.」 ； Then leave a life for it in Settings → General → Background App Refresh ； The most stable solution is to set the router to "resident" or enable a real-time channel in the App. Some models of ASUS and Xiaomi have this permanent option. Android doesn’t pay so much attention. Just add the app to the battery whitelist. Don’t let the system kill it with one-click cleanup.

Don’t panic if your family is full of elderly people. There is a simple way.: Turn off notifications and change it to the total number of devices that glance at the app's homepage regularly every day. Next to the WiFi QR code posted on the entrance of my house, I now use a marker to write "23 connected devices." I check the numbers every now and then. If there are more, there is something wrong. Soil is soil, it works.

The verification switch is really on: Plug in an old cell phone

When this switch is turned on, you can't count it by just looking at the light on. It needs to be measured actually. After installing five devices that time, I took a charged Redmi Note5 from the drawer, forgot its WiFi record, and used it as a brand new device.: Enter the wrong password once to establish its "new device" identity, then enter the correct password again. The notifications popped up on the four devices on the spot. The fastest Asus one took less than two seconds, the Mijia one took about three seconds, and the Mercury one took half a minute. The push link for the public version of the firmware was indeed a bit slow, but it finally arrived. The Tenda unit didn't play. I went back to the background and saw that the binding relationship had expired. I logged in to the App again to bind, and the second test was normal.

During the test, take note of the three things given in the notice.: Device name, first six digits of MAC, and assigned IP. The first six digits of the MAC are the manufacturer's code. If you search it, you will know which device is produced by which company. For example, the code starting with DC:36:45 is probably a TV box. This skill of recognizing relatives has been used before Recognize device in background That article was written in more detail, and I could label all the dozens of Unknowns at home.

Say one more thing: When the notification comes, don’t rush to block it. My mother-in-law's house had a "new device iPhone", and the old lady was so frightened that she called and said that she was being targeted by hackers. I looked remotely and saw that it was the network connection for her newly purchased hearing aid - today's hearing aids must be connected to WiFi to push firmware. Recognize it first, and then take action after recognizing that it is a stranger. The number of ways to take action is Cha Ceng.com In that article.

In addition to the reminder, I conveniently repaired the two locks

Only the reminder is "visible", but something needs to be added to make it "not accessible". That night I made up all three items at home.:

• The WiFi password has been changed from the last number of the mobile phone back then to a 16-digit random string, and there is a separate password for the management backend. How to choose a password that is both safe and not afraid of being lost by the TV? I have gone through it and wrote it down. Do you need to add special characters to the password? In that article
• I set up a guest network for my parents' house, and when relatives come over, they always connect to the guest network, but the main network password is never used again. How to open the guest network and configure the speed limit? Guest network settings There are complete steps in
• Check that the router firmware has been updated. The firmware of the Tenda AC10 in my hometown was stopped three years ago. Several security patches were released in the past but were not applied. The WPS vulnerability of the old firmware was exploited by master key tools. I wrote an article about this principle. The truth about the four-way handshake and the master key

Don’t mess up the order: Start the reminder first, then change the password, and finally finish. If you change the password first, more than a dozen smart devices at home will lose contact on the spot, and you will be scrambling all night between popping up notifications and reconfiguring them one by one. I have experienced that tragedy, and the rescue methods for the four types of devices are written in Disconnected after changing password In that article, if you can't take this step, don't take it.

Which machines cannot enable this reminder? What should I do?

It is true that some old machines and no-name machines cannot be turned on. My cousin’s white-brand router was given by the operator four years ago. I can’t access the app. The backend of the webpage is broken and there is no reminder function. Don't waste money on this kind of thing. The three choices are arranged according to cost.: One is to recognize it directly and check the device list in the background regularly. ； Spend only 280 yuan to switch to a big-name entry-level phone, and these reminders about the new firmware are standard. ； If there are old idle routers in the three homes, it can be achieved by flashing OpenWrt and installing a notification plug-in. However, the threshold of this road is high, and it is not recommended to start it for the first time if you have not tried it before.

Just don’t expect the WiFi reminder from Moo. I have checked all the gateway backends of Tianyi, China Mobile, and China Unicom. There is no new device push function for users, and the operators don’t care about this. If the WiFi at home is mainly provided by the optical modem, the trick taught in this article can only be used if the router takes over the WiFi.

Finally give it all: This set of reminders prevents "unknown people from coming in" and cannot prevent people from using tools to break through. If you really live in an apartment building or next door, you know what to do. Notifications alone are not enough. You have to add them to the whitelist, increase the password, and turn off WPS. But for 90% of families, this level of notification is enough - in the six months since my cousin's incident, there have been three new equipment notifications at home, two for hearing aids and sweeping machine replacement modules, and one for my own new laptop. Never seen a stranger again.