How does Xiaomi router work? 4C: Technical features and hidden opportunities

Router Xiaomi Router 4C — One of the most popular budget routers from the Chinese brand, which, despite its modest technical characteristics, continues to hold its position in the market due to the optimal ratio of price and functionality. Launched in 2018, the device has been a hit with users who want a simple but effective home networking tool, but its minimalist design and concise interface hide features that many people don’t even know exist.

In this article, we will discuss in detail how Xiaomi Router works. 4C at the hardware and software level: from the processor architecture to firmware features, from basic settings to advanced functions like VLAN And QoS, you'll learn how the device handles traffic, why it sometimes slows down Wi-Fi, and how to get the most out of it, even in 2026. And then you'll learn a few hidden commands to access advanced settings through the Internet. SSH, which are not dokumented in official instructions.

Hardware platform: what is inside Xiaomi 4C

Under the plastic case of Xiaomi Router 4C It hides the hardware platform typical of the low-cost routers of its day. MT7628AN — A solution that was widely used in low-cost routers in the early 2010s, and it runs at 580 MHz, and it has a built-in Wi-Fi module. 802.11n (up to 300 Mbit / s at a frequency of 2.4 GHz).

Key components of the platform:

• 🔹 RAM: 64 MB DDR2 — This is enough for basic routing, but can become a bottleneck when a high load is used (for example, when connecting 10).+ device).
• 🔹 Flash memory: 16MB SPI NOR — It's a small volume, but it's enough for standard tasks.
• 🔹 Ethernet ports: 2× 10/100 Mbit/s (one Mbit/s) WAN, single LAN) controller-based MT7628. Lack of Gigabit ports is the main limitation of the model.
• 🔹 Antennas: 2 external non-removable with gain of 5 dBi - provide a stable signal in a small apartment.

Feature MT7628AN — Support for hardware acceleration NAT (Network Address Translation, which allows the router to efficiently process traffic even at modest computing power, but when additional functions are activated (for example, VPN-Server or Parental Control performance may fall due to load on CPU.

⚠️ Note: If you are planning to use Xiaomi 4C If you are on a network with Internet speeds above 100 Mbps, please note that due to the limitations of Fast Ethernet ports, the real speed on the cable will not exceed 94 Mbps (including service traffic.

Software: firmware and its capabilities

Xiaomi Router router 4C It works on the basis of the firmware MiWiFi ROM, The management interface is a web panel in Chinese or English (Russian only appears after manual installation of the language pack:

• 🌐 Cloud management: Xiaomi account binding allows you to manage your router via the Mi Wi-Fi mobile app (available for Android and iOS).
• 🔒 Guest network: support for an isolated network for guests with a separate password and limited access to local resources.
• 📊 Traffic monitoring: built-in tools for analyzing network usage across devices (with a time limit on data storage).
• 🔄 Backup: Ability to save and restore settings through a configuration file.

However, standard firmware has disadvantages:

• ❌ Lack of support IPv6 (It is relevant for some providers).
• ❌ There is no built-in AdBlock or content filtering.
• ❌ Limited QoS (Quality of Service) settings).

Some of the problems are solved by installing custom firmware, such as OpenWRT or Padavan, which extends the functionality by adding WireGuard support, SQM To combat buffering, as well as more flexible network settings, but the firmware process requires caution - if you make a mistake, the router can turn into a brick».

How a router handles traffic: routing and NAT

The main task of any router is to route packets between devices on the local network and the external Internet. 4C This process is implemented using the mechanism NAT (Network Address Translation, which allows multiple devices to use one external device IP-So let's look at the address provided by the provider:

1. Packet Reception: When a device on a local network (such as a smartphone) sends a request to the Internet, the packet arrives at the port. LAN router.
2. NAT-Transformation: Router replaces internal IP-the device address (e.g. 192.168.31.100) to its external IP, assigns a new port to the packet and records this mapping in NAT-chart.
3. Routing: Package is sent through the port WAN to the provider, which then redirects it to the target server (for example, to the site).
4. Backward path: When the server sends a response, the router is ported and external. IP finds NAT-The original device and sends the packet to it.

Xiaomi. 4C symmetrical NAT (Cone NAT), It's a system that strictly binds response packets to outbound connections, and it can cause problems with some of these. P2P-applications (e.g. Torrent or Discord) because external nodes cannot initialize a connection to the device behind the device. NAT without prior request.

If you need to configure port forwarding for the game server or IP-Cameras, do this through the web interface in the Advanced Settings section → NAT Forwarding. For example, to roll the port 8080 to a local device with IP 192.168.31.100 Use the rule:

External Port: 8080


Internal IP: 192.168.31.100




Internal Port: 8080




Protocol: TCP/UDP

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If the connection is not working after port rolling, check if the provider’s firewall blocks traffic. Some operators (for example, Rostelecom) by default close incoming ports on their equipment.

Wi-Fi Module: Why Signaling Can Be Weak

Despite the stated speed of 300 Mbps (standard) 802.11n), Real Wi-Fi performance in Xiaomi 4C It's often left much to be desired:

1. Chipset limitations MT7628AN: This module supports only one stream. MIMO 1×1, While more modern routers are used 2×2 MIMO or 3×3 MIMO, which increases the capacity of.
2. Transmission power: In some regions (for example, in Russia) the power of Wi-Fi transmitters is legally limited to 100 mW, which reduces the signal range.

To improve coverage, follow the following steps:

For manual channel selection, go to Wi-Fi Settings → Advanced and set the Channel to the lowest interference setting, and you can check the loading of channels using applications like Wi-Fi Analyzer (for Android).

⚠️ Note: If you are using a router in repeater mode (WDS), Wi-Fi speed will drop by half because of the need to relay the signal. 4C cable-way.

Hidden functions: access through SSH and extended settings

Official MiWiFi firmware ROM It hides many useful functions, but can be activated through SSH-That's what access is:

1. Turn it on. SSH In the web interface: go to Advanced Settings → System Tools → SSH and activate the option.
2. Connect to the router using the PuTTY client (Windows) or terminal (Linux/macOS) address 192.168.31.1 with root login and password from the sticker on the bottom of the device.

Some useful teams:

• 📌 nvram show | grep ssid – show current Wi-Fi settings.
• 📌 iwpriv ra0 set Channel=6 – Forced to change the Wi-Fi channel.
• 📌 Top – display the current load on the processor and memory.
• 📌 cat /proc/cpuinfo — processor.

For power users, deeper settings are also available, such as changing Wi-Fi transmission power (default limited to 20 dBm):

iwpriv ra0 set TxPower=27

However, an increase in power above the permissible values may violate local legislation and lead to overheating of the module.

Optimizing Productivity: What Can Be Improved

Even with the modest features, Xiaomi Router 4C You can “stop” with a few tricks:

1. Disable unnecessary services: Deactivate UPnP in the web interface, DLNA and FTP-server if they're not in use, it'll reduce the processor load.
2. Use an alternative. DNS: Replace. DNS Provider at 1.1.1.1 (Cloudflare) or 8.8.8.8 (Google) in the Network section → Internet.
3. Limit the number of connected devices: If more than 15 devices are connected to the router at the same time, performance drops due to a lack of RAM.
4. Set up QoS: Prioritize traffic for important devices (like Smart) TV or working laptop) in the Advanced Settings section → QoS.

For users willing to go further, there is an option to install Padavan firmware, which adds:

• 🔧 Support for WireGuard VPN.
• 🔧 Extended Firewall settings.
• 🔧 Monitoring the temperature of the chipset.
• 🔧 The ability to connect an external drive (through USB, if you refine the hardware).

The firmware process is described in the forums 4PDA OpenWRT, but requires soldering work to connect UART-console in case of failure.

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If you're Xiaomi. 4C It can be overheated, or it can be overheated, so the solution is to provide better ventilation (e.g., to put the router vertically) or reduce the load by turning off resource-intensive functions.

Typical problems and their solutions

Despite the reliability, Xiaomi Router 4C They may be facing typical problems, and these are the most common and the ways to fix them:

If the router stopped turning on (all indicators are on or not responding to the power button), this may indicate a hardware failure. 80% of the time, the fault is a capacitor in the power chain, repair will require a soldering iron and experience with electronics.

FAQ: Answers to Frequent Questions