Is the Xiaomi AX3600 still worth buying? Bought a second-hand dedicated 2.4G feeding unit for 95 yuan, and the problem of 40 smart devices disconnecting at midnight didn't happen again for a month

the old AC2100 at home was upgraded to a wired relay IoT private network, which I installed two years ago: old machine single-transmitter 2.4G dedicated to feeding smart device , the main router is quiet. This setup was peaceful until last month, when the Mi Home app started dusting at two or three in the morning: first the living room speakers, then the vacuum cleaner, two lights, and a thermo-hygrometer—seven or eight units in a single smolder. Out of about 40 smart devices, a few always fail every day. Restarting them works fine, so I'll try a new batch in a couple of days. I the order in the offline device article, removing cloud, signal, and firmware, and finally settling on the AC2100: it's just too old. 95 yuan, Xianyu bought a second-hand Xiaomi AX3600 to take over.

first clarify what kind of platform the AX3600 is

AX3600 is the device released in February 2020 alongside the Xiaomi 10, launching at 599 yuan. Xiaomi's first-generation WiFi 6 flagship, with its full name even "AIoT Router." The selling points from back then are still competitive today: Qualcomm IPQ8071A six-core chip, four CPU cores plus two NPU network acceleration cores, 14nm process; 512MB of memory, double the AX3000T still on sale today; The 5G band has a 4x4 specification, with 2402Mbps at 160MHz bandwidth, and 2.4G at 574Mbps on 2x2. Additionally, there is a dedicated AIoT antenna to detect Mijia devices. The official claim is 248 units with built-in devices. When I first saw this number, I was stunned for a moment—almost double the AX3000T's claimed 128 units.

shortcomings also need to be exposed: three gigabit LAN ports plus one gigabit WAN port, no 2.5G, no USB—this is the 2020 rule and cannot be changed. The official firmware has long stopped being updated, so don't expect security patches. So the positioning of this machine is very clear now—solid hardware, reliable software, perfect for private network work.

Why do IoT private networks require WiFi6

let me first explain my family background: the entire house has 62 devices which have been significantly slimmed down, including about 40 smart hardware like light bulbs, sockets, sensors, and cameras, all nailed to the IoT private network 2.4G. These devices share one thing in common—the flow rate is pitifully low, and a thermo-hygrometer sends several bytes per minute, but it speaks. 2.4G channels only allow one device to speak at a time; the old WiFi 5 rule is everyone queues up and each person takes a round. Even if each person only posted one message for 40 devices, the queue would stretch to the door.

WiFi6 OFDMA changed this queuing mechanism: a speaking opportunity was split into several small slots, and four or five devices were sent out at once. I've written about the principle of OFDMA lane drawing before, just a concept at the time, but now it's really happening—the more equipment and smaller the package, the greater the OFDMA profit. My booth with 40 small bags happens to be its main battleground. The AC2100's 2.4G is WiFi 5, but it doesn't have this capability. During the late-night reporting period, the air port queues overflow, and the router treats slow-responding devices as disconnected. This explains those waves of collective graying.

there's another issue in the phone swap: when choosing protocols, I've calculated the trade-off between WiFi direct connection devices and gateway devices. My Zigbee batch at home uses the gateway but doesn't occupy space, and all the remaining WiFi direct connected devices are regular users of 2.4G. Giving this to a new device with strong 2.4G capability is the most effective way to spend this on the right approach.

95-yuan used phone? Never touch a modded phone

AX3600 second-hand market has been very stable these past two years. On Xianyu, it's 90 to 110 yuan, and a good condition with the original box at 120 is normal. But this price range is also tricky: be cautious of machines that are 20 or 30 years cheaper. Some sources are machines that have been flashed with OpenWrt or heavily modified to RouterOS, so sellers want to sell quickly. If you don't know how to flash your phone, don't even accept these free giveaways—flashing versions is completely different from what you expect from official firmware, and checking them can drive you crazy. My principle is simple: buy retired home consoles that have been using official firmware, not leftover devices left over.

I came right on time for the inspection, five steps: First, ask the seller if the firmware is officially in use, then hesitate and refuse directly; 2. Power on and check the lights; if the orange light turns blue and stays on, it is considered normal starting; 3. Check the bottom shell to see if the SN stickers are present and if the antenna root is cracked—AX3600 has seven external antennas, and squeezing cracks at the roots during transport is a common issue; 4. Log in to 192.168.31.1 to check the system status. If you can access the backend and the firmware version is in the official format, there should be no major issues; 5. Check if the power supply is original. This device consumes a lot of power, and if you use a random generic adapter, it won't work well for a long time. the inspection approach I used last time to buy the Redmi AX6000 also applies, so you can look at it face to face. No matter what the seller says, once you get it, you can restore it from the factory and then bind it to Mijia with your own account—it's clean.

Getting started settings: Wired relay, only 2.4G, name copyed

wiring is done in the opposite way from other brands: plug the incoming cable into the AX3600's WAN port, which is the blue port—Xiaomi's wired trunking rules are like this. The AP mode article specifically covered this pitfall, so just copy it as is. Then go to the background 31.1, switch to the working mode → the commonly used settings → internet settings, select the wired relay, and wait for it to restart. After restarting, the management IP will drift. Don't panic—check the main router's device list to find what the IP is now called. This step is most likely to be mistaken for a broken machine.

followed with three things. First, turn off the dual-band integration and switch the 5G switch directly off—this machine acts as an IoT gateway, only sending 2.4G. The 5G frequency overlap with the main router's 5G band is just disruptive; the 4x4 2402Mbps is just pretended to be nothing. Second, the WiFi name and password are not changed at all, just copying the old AC2100's IoT network name. This is the easiest way to replace devices: device recognizes a combination of name and password, not a machine the same name. You can switch between 40 devices without needing to reconfigure the network — anyone who's experienced it understands the pain of reconfiguring a robot vacuum. Third, the channel is manually pinned and misaligned with the main router: My main router is 2.4G at 6, but this one is pinned to 11. the automatic channel jumped out at midnight and killed the IoT device. I've encountered this once before, but never dared to let it automatic.

After setting up all the

, I connected my phone once to confirm it could get online, then powered off and retired the old AC2100, switching everything within half an hour. Don't throw away old machines—clean them and put them in drawers. Backup machines will come in handy one day.

real experience after a month of use

first mention what matters most: a group disconnect in the middle of the night, and it hasn't happened again for a month. The only time was when the corridor speaker fell off. After restarting, it restored itself without affecting others—this kind of isolated incident has little to do with the router; it's the device's own firmware jamming. The change in response speed is even more obvious than disconnection: when the Mi Home app lights up, it used to turn on for one or two seconds, but now it basically lights up as soon as you tap it. This is how OFDMA integrates small packets, so 40 devices no longer queue individually or squeeze in with a single command.

also has a price to be paid for. Power consumption is much higher than the AC2100. The seven antennas are plugged in year-round, and the annual electricity bill is over ten yuan—I accept it. The 5G 4x4 is completely idle, which is honestly a bit of a shame, but you can't expect a 95-yuan machine to make full use of every antenna. As for those wanting to use it as the main router—512MB of RAM and 248 routers are qualified, but the firmware stops and doesn't have a 2.5G port. If it becomes the main router again in 2026, it'll be barely enough. my main router AX3000T has been used for two years is much more reassuring. There's another backup plan worth mentioning: IPQ8071A this platform is an evergreen of Enshan Mountain, and OpenWrt support is quite mature. If you ever don't want it to be an IoT gateway, you can unlock SSH and flash third-party firmware or use it as a bypass router. This machine offers much more room for use than newer phones at the same price point.

who is worth taking, and who should you avoid

this machine isn't appealing to everyone, I've compiled my thoughts for the month into a single table:

let's give a straightforward order of decision-making: count the devices first, with fewer than twenty smart devices, and one person handling the main router, so there's no need to buy one; If there are more than thirty units and disconnection issues, consider buying another unit. Before buying, make sure the main router has an unused LAN port; if not, add a switch first. Follow the five steps above to inspect the device upon receipt: restore the factory upon receipt, switch to wired relay, only ship 2.4G, copy the name directly, stagger the channel—these five steps complete the job. If the budget could be relaxed to 200 yuan, I wrote about how to choose among the three budget tiers. I've written that the brand-new ones are AX3000T much more worry-free; The 95-yuan AX3600 is all about the cost-performance ratio of an "old flagship doing new work."