How to set up too many smart devices on the router? I connected the camera and sweeper to a separate WiFi, and the mainnet was up that night.

The list of WiFi equipment in my home during last year’s Double Eleven had this formation.: There are 4 mobile phones, 2 laptops, 2 tablets, 3 cameras hanging underneath, 1 sweeper, 2 speakers, 1 TV box, 7 smart sockets, 78 sensors, plus the old mobile phones brought by the mother-in-law, a total of just over 30 units. The problem started half a year ago: The sweeper stopped on its own in the middle of the night, and the camera went offline every once in a while. The lag when I played games jumped up around 8 or 9 p.m., and the speed measured was over 400 Mbit/s. Everything looked normal, but nothing was right.

After a whole night of flipping through the device list in the backend of the router, I figured it out.: This is not because the network is slow, but because the "resident composition" on the Internet is too complicated. Mobile phones and computers need to be fast, and smart devices need to send small heartbeat packets all day long. They are all crowded on the same WiFi, and routers have to take care of them one by one. There is only one thing I do - move the entire batch of smart devices to a separate WiFi. The night after the move was completed, the game's lag was stabilized, and the sweeper didn't crash again for a month. This article writes down the entire operation and four implementation methods. If you have more than 10 or 20 smart devices at home, just copy them.

Think about it first: The problem is not "the Internet speed is not enough", but "the two types of devices cannot cope with it"」

The network requirements of smart devices and mobile computers are basically two different animals. What mobile phones and computers need is throughput - how many megabytes can they give me in one second? ； What the camera sweeper wants is the online rate - I don't want the bandwidth, what I want is the router, don't forget me. Smart devices usually send heartbeats of a few KB, but you can't handle it sending them all day long, and most of them are stuck on 2.4G. The 2.4G frequency band is inherently narrow, and more than 20 of the 30 devices in your home are all in it. Coupled with the signals from neighbors, the router is queuing up to work on 2.4G.

There is another one that is inconspicuous but very hurt.: As there are more devices, the traffic of broadcasting and "shouting" between devices on 2.4G increases. This kind of traffic does not work but takes up air. I checked the number of connections on my router in the background, and the number of connections on 30 devices was more than when I connected BT alone. I am concerned about the number of connections. What happens when the number of router connections is full? After the calculation, the ledger was full and the router directly rejected the customer - the smart device went offline. In many cases, it was not because the signal was poor, but because it was squeezed out of the door.

So the solution is not to replace the Gigabit router or increase the bandwidth, but to separate the two types of households. Mobile phones and computers live on the main network, and smart devices are moved to a separate WiFi. After we separated, the 2.4G traffic jam immediately eased. My mobile phone should be connected to 5G without disturbing each other. How to count the equipment list at home, what equipment uses which frequency band, I am The article about 49 smart homes Record the accounts one by one, count them clearly before starting.

The first route is zero cost: Open a "device-specific WiFi" in the background」

The main router I use is Xiaomi AX3000T, which has a ready-made function in the background.: There is no need to touch the existing main WiFi, just create a new SSID specifically to feed smart devices. The path is entered by the browser 192.168.31.1 , find the WiFi settings in the common settings, click to add a WiFi, and give it an easy-to-understand name. For example, the one in my house is called "jia-shebei", and the frequency band is designated 2.4G - most smart devices only recognize 2.4G. Don't be too quick to turn on 5G. If the camera cannot connect, you will have to rework it. Don’t use special characters in your password. Use 12 letters plus numbers. I’ve suffered this mistake before.: The main WiFi password has a hash mark, and the camera cannot be connected to the network. I changed it to a pure alphanumeric one and got over it. This is a pitfall for me. Do you need to add special characters to your WiFi password? I wrote that specifically.

When a new WiFi is turned on, choose one of channels 1, 6, and 11 that is staggered from the main network - the main network 2.4G is fixed to 6, and the dedicated one is fixed to 11. The two networks have different channels, so the degree of mutual interference will be reduced first. Here’s how to choose a channel How to check WiFi channel interference In that article, I wrote about installing an analyzer app on your phone and scanning it. Then I re-distributed the network from device to device and connected it to the new name. This step was physical but not technical. It took me two nights to move 30 devices.

Other brands have different names for this function.: ASUS calls it multi-SSID other than unlimited communication/guest network. Some models of TP-LINK add guest network 2.4G exclusively in wireless settings. Mercury Tenda's new firmware also allows adding one more in "WiFi settings". The core is just one sentence: As long as your router can open an additional 2.4G network, this path will work. If you can't find the option of multiple SSIDs in the background, look down at the second option, the guest network is just fine.

The second way is still zero cost: The guest network acts as a “device shelter”」

There is basically a guest network switch in the background of the router. It is intended to be connected to guests. In fact, it is suitable for housing smart devices.: It is inherently a 2.4G network independent of the main network. The password is set separately and has no connection with the main WiFi. My mother's old TP-LINK didn't have multiple SSID functions, so I moved all her cameras and doorbells into the guest network. After moving her phone, she was able to view videos much more efficiently - the old lady commented that "the TV doesn't spin anymore."

There are three things you need to confirm in the backend when using the guest network, otherwise you will get into trouble. The first thing is that the guest network is isolated by default, which means that the devices on this network cannot see each other. Smart devices with network linkage may cause problems: Bluetooth gateway accessories must be on the same network as the main device before they can be paired. This category is moved. The second thing is that some firmwares automatically turn off the guest network when the time comes (some call it time-limited turning on). When the cameras are moved in, they all go offline in the middle of the night. Go and turn off the timer. Where is the timer switch? Router disconnects regularly In that article, the positions of each brand were recorded. The third thing is that some firmwares limit the bandwidth of the guest network by default. If the home firmware has this option, it would be reasonable to limit the network to the camera to 20Mbps. It will not be used up anyway, and it will prevent it from getting out of control.

The upper limit of the guest network path is also clear.: After all, it is designed for temporary visitors. If there are too many devices, the firmware may not be able to withstand it. I actually measured that 8 devices in my mother’s home are stable. If you have 30 or 40 devices in your home, the first or fourth path is more reliable.

The third road costs a few dozen yuan: VLAN on the managed switch and build a wall from the line

The first two paths are "logical separation" - the names are separated, but the two networks are still running on the same router and the same set of hardware, and broadcast packets still pass through the bridge. My family ended up going to Article 3: I bought an 8-port managed switch for 60 yuan and used VLAN to circle the smart devices from the link layer. The router, TV cabinet, and wall where the cameras are concentrated each pull cables into the switch. Two VLANs are drawn on the switch, one for the main network and one for the equipment network. VLAN is a wall built by the switch chip at the forwarding level. The broadcasts and heartbeats of smart devices cannot even be touched by the main network door, and the isolation is much more complete than the first two paths.

An unexpected gain by the way: My TV box became safe after being included in the device network. In the past, it was on the same network as my NAS. The box would scan for devices on the LAN every three days and look through my shared folders. I used the packet capture tool to see everything clearly. Once the VLAN is installed, it can no longer even see the NAS door. For the complete troubleshooting process and VLAN configuration details of this "TV box scanning NAS", I am here Router VLAN article I have memorized the whole process, and if I want to take this path, I will follow that article.

This road is suitable for two kinds of people: Those whose homes have already been wired with network cables, or those who have high requirements for isolation (the camera involves privacy, so you can sleep safely if you circle it). If your home relies entirely on WiFi and you don’t want to pull any open wires, don’t force it and look down the fourth path.

The fourth way is to eat ashes and turn into treasure.: Turn out an old router and feed it to smart devices

If you have an old retired router in the drawer at home, the price/performance ratio of this method is unmatched. What I dug out was an old AC2100 from eight years ago. I connected a network cable from the main router LAN port to its LAN port, turned off its DHCP and let it function as a pure AP, specifically sending out a 2.4G device WiFi. It doesn't matter if the performance of the old router is weak - smart devices want stability, not speed. The old machine with more than 20 heartbeat devices is more than enough, and the main router is suddenly clear.

There are two pitfalls to avoid in the connection method. The first one is that when the old router is used as an AP, DHCP must be turned off. Otherwise, both machines will be issued house numbers, and the device will get two gateways and the network will be convulsed. This is what I am doing. Router used as switch In that article, the three connection methods and their respective pitfalls were laid out and marked accordingly. Second, if the LAN port of the old router is 100Mbps, it won’t be a problem. Smart devices can use a few Mbps, but you have to know that if you don’t connect mobile phones and computers to this network, it will be dragged down to about 94Mbit by the 100Mbps port. I’m here to account for this. WAN port speed That one has passed. Xiaomi users also have an advanced way to play: I bought a second-hand AX3600 designed for 2.4G. WiFi6’s performance is much better than the old machine when dozens of small devices are online at the same time. I’m here The AX3600 article After a month of actual testing, you can tell whether it is worth reading.

How to choose among the four paths?: Seat according to family conditions

I went through all four roads and compiled them into a list according to "which way to take according to the conditions at home." You can choose according to the situation of your own home.:

My suggestion is to try this order: First check to see if the SSID can be added in the background (it only takes five minutes for a penny). If not, check the guest network. If both are awkward and you happen to have an old route at home, just go to the fourth option. VLAN is reserved for households with wired networks or where camera privacy is a tight concern.

Which equipment should never be moved, and how to inspect it after moving it?

Not all smart devices should be moved. I’ll point out for you the three types of pitfalls I’ve encountered.: First, the device needs to be discovered on the same network as the mobile phone - the mobile App searches for the device and finds it locally (such as TV screencasting). The mobile phone is connected to the main network and the device is on a dedicated network. If the App cannot find it, it means it is separated by the network. I use screencasting and other methods. mDNS article The principle has been explained here. To find out across networks, you need to enable cross-network forwarding on the router, which most household firmware does not have. The second one is with a local linkage gateway (Bluetooth gateway, Zigbee gateway, etc.). The gateway must be on the same network as the linked device. The third is that those who work on the main network rely on fixed IPs (NAS, printers). They are already stable on the main network. Don’t be itchy. I have the rules for static IPs. The article about binding static IP It has been written here that moving the network segment is equivalent to invalidating the binding.

Don’t look at the feeling after moving, look at the data. My acceptance actions are threefold: On the other end of the smart device, click on the channel one by one to check the online status. If it is stable and does not drop out for three days, then it is considered ； On the mainnet side, we measured the latency and speed during the peak period of 8 or 9 pm, and compared the numbers before the move. ； Check the IP list of the device in the background to confirm that no mobile phone or computer is included in the dedicated network segment. If you are not worried about the status of your smart device in the middle of the night, you can check the router log to find the record of disconnection and reconnection. Here is how I can check it. Check the router log I wrote in it - I turned over it every day in the first week after moving, and I didn't dare to let it go until the second week.

wrap up: Separating a house is not about changing equipment, it is about dividing the residents into opposite floors.

My biggest experience with this is: Routers "cannot carry" smart devices. 90% of the time, it is not because the performance is insufficient, but because all the devices are mixed on the same network and drag each other down. Allocate mobile phones, computers and smart devices to two WiFi networks. A router worth 200 yuan can carry 30 devices without spending a penny. The final form of my home is that the main network AX3000T sends 5G and main 2.4G, the old AC2100 is used to feed the device WiFi, and the VLAN on the switch blocks the camera path. When my mother-in-law came to stay, her old mobile phone was connected to the main network, and the speakers of the sweeper were all on the dedicated network. The two groups did not disturb each other. I remember clearly what she said when she left.: 「Why did this network suddenly become better? 」It's not sudden, it's because I moved home for two nights.