Reflashing of the Xiaomi Redmi AC2100 router: from stock MIUI to OpenWRT

Xiaomi Redmi router AC2100 (model RAC2100) — popular device with powerful iron (dual-core processor) MT7621A, 128 MB of flash memory), but factory firmware based MIUI Users face problems: lack of support VPN-Server locks, port locks, forced cloud binding to Xiaomi. Flashing to alternative OSes (OpenWRT, Padavan) solves these problems, but requires accuracy - an error can turn a router into a brick".

This guide contains three proven ways to reflash Redmi. AC2100 (web-based, SSH regimes U-Boot/TFTP), And we'll also show you how to pick the right firmware version, avoid loss of warranty, and set up your router after the upgrade (2026 year).

1. Preparation for flashing: what you need to know before you start

Before you start, make sure your Redmi AC2100 meets the following key requirements:

• 🔹 Hardware version: firmware must match the board's revision, and you can find it on the sticker under the router (see the labels). PCB v1.0, v2.0 etc. For AC2100 version v1.0 (2019–2020) and v2.0 (2021–2023.).
• 🔹 Current firmware: stock MIUI (Version below 2.2.0 may not support alternative OSes. → Status. → Firmware version.
• 🔹 Backup: Save current settings (export configuration to Settings) → Additionally. → Backup) and data of connected devices.

Critical risks of flashing Redmi AC2100:

• 🚨 Loss of warranty: Xiaomi cancels warranty obligations if third-party software is detected.
• 🚨 "Bricking: Incorrect firmware or interrupted process can make routers inoperable.
• 🚨 Wi-Fi problems: Some alternative firmware (such as early OpenWRT builds) don’t work properly with the chip MT7615N (responsible for 5GHz).

⚠️ Note: If your router is purchased in China (model with suffix) CN), In the stock firmware, access to the SSH. An additional procedure will be required to unlock.

2. firmware selection: OpenWRT vs Padavan vs stock MIUI

Each firmware for the Redmi AC2100 has pros and cons. Below is a comparison table of key parameters:

For most users, the best choice is Leedee’s Padavan firmware (MT7621 version), which combines the flexibility of OpenWRT with the convenience of a web interface and stable Wi-Fi.

Where to download firmware:

• 🔗 OpenWRT: Official repository (link) or forum 4PDA (Xiaomi Redmi AC2100). Look for the assemblies marked mt7621.
• 🔗 Padavan: GitHub by Leedee (link). AC2100 fits the file with the name r6220-padavan-*.trx.
• 🔗 Stock-stock MIUI: Xiaomi official website (link) Choose the latest version for your fee revision.

💡

Before downloading the firmware, check its hash amount (MD5/SHA256) using the CertUtil utility on Windows or the md5sum command on Linux.

3. Method 1: Flashing through the web interface (the most secure method)

This method is suitable for updating stock MIUI or installing Padavan (if the current firmware supports third-party downloads). It does not work for OpenWRT - it can only be installed via SSH or U-Boot.

Step-by-step:

1. Download the firmware (a file with the.bin or.trx extension) and rename it miwifi.bin (this is mandatory for a stock bootloader).
2. Connect to the router via cable (Wi-Fi may shut down during the process).
3. Go to Settings → Additional → Update firmware.
4. Click "Select File", download miwifi.bin and confirm the update.
5. Wait for the reset (5-10 minutes). Don't turn off the power - the indicator should flash orange, then light up blue.

⚠️ Note: If the router does not load after flashing (all indicators are on or red flashes), then the firmware file did not fit the board version.

Download the correct version of the firmware|Rename the file to miwifi.bin|Connect to Ethernet cable|Disable firewall/antivirus on PC|Charge your laptop (in case of power outage)-->

Method 2: SSH Installation (for OpenWRT and custom builds)

This method requires prior unlocking. SSH-If you have a router with a Chinese version MIUI (suffix CN), SSH Default is disabled - see the unlock instruction.

Instructions for OpenWRT installation:

1. Connect to the router via SSH (login: root, password: password from the admin panel or empty). Command: ssh root@192.168.31.1
2. Download the firmware directly to the router: wget https://downloads.openwrt.org/releases/23.05.0/targets/ramips/mt7621/openwrt-23.05.0-ramips-mt7621-xiaomi_redmi-router-ac2100-squashfs-sysupgrade.bin
3. Start the firmware process: sysupgrade -v openwrt-*.bin
4. Wait until the router is finished (it will restart automatically). OpenWRT takes up to 5 minutes to launch in the first place.

After installation:

• 🔌 The OpenWRT web interface will be available at 192.168.1.1 (login: root, no password).
• 🔌 Set up the network manually: by default DHCP-server down.
• 🔌 Install the LuCI management packages (web interface): opkg update & & opkg install luci

5. Method 3: Firmware via U-Boot/TFTP (for recovery)

This method is used if the router does not boot (for example, after a failed firmware) or if you need to install OpenWRT on a "clean" system. TFTP-server.

Algorithm of action:

1. Install. TFTP-server on a PC (for example, Tftpd64 For Windows, place the firmware file (renamed to miwifi.bin) server-folder.
2. Connect the router to your PC via Ethernet (LAN1-LAN3 ports, WAN ports do not use!).
3. Press the Reset button on the router and turn on the power. Hold the button for 10-15 seconds until the indicator flashes quickly orange (U-Boot mode).
4. Set up static IP 192.168.1.2/24 on your PC and send the firmware via TFTP: tftp -i 192.168.1.1 PUT miwifi.bin
5. Wait until the download is complete (U-Boot will have an Upgrade successfully message).

Firmware recovery via U-Boot is possible even if the router does not respond to the buttons.

• 🔧 Use the official recovery file (recovery.bin) Xiaomi.
• 🔧 If TFTP It does not work, try stitching through the serial console (a soldering iron is required and USB-TTL adapter).

💡

Firmware via U-Boot/TFTP is the only way to restore the router after serious crashes, but requires accurate timing (the delay when holding the Reset button should not exceed 20 seconds).

6. Unlock SSH on Chinese versions of Redmi AC2100

Xiaomi Redmi AC2100 routers with firmware for the Chinese market (CN) have blocked SSH.

1. Download exploit from 4PDA (script ssh_enabler.sh).
2. Connect to the router via Telnet (temporary access opens for 5 minutes after turning on): telnet 192.168.31.1
3. Run the script in the terminal: sh ssh_enabler.sh
4. Restart the router. SSH will then be available by default.

Alternative method (for firmware older than 2.0.10):

• 🔓 Use the Mi Router Unlock Tool (available on GitHub).The tool automates the process but requires you to connect to the router via a router. USB-TTL.
• 🔓 On some versions MIUI Unlocking is possible through changing the region in the settings (Settings) → Additionally. → Region → Choose Russia or Global).

7.Router Recovery After Failed Firmware

If the router doesn’t turn on (all indicators are on or red flashes), try the following steps:

1. Reset to factory settings: 🔄 Press the Reset button for 30 seconds (until blinking in orange). 🔄 If the reset doesn't help, go to U-Boot (see Method 3).
2. Firmware through the serial console (requires dismantling of the router): 🛠️ Connect. USB-TTL contact-adapter TX/RX/GND on board (spinning for AC2100: GND → GND, TX → RX, RX → TX, tension 3.3V). 🛠️ Use PuTTY (Speed) 115200 baud) for access to the console. 🛠️ Enter the commands for firmware through TFTP: setenv serverip 192.168.1.2 setenv ipaddr 192.168.1.1 tftpboot 0x80000000 miwifi.bin erase 0xbc000000 +${filesize} cp.b 0x80000000 0xbc000000 ${filesize} bootm 0xbc000000

⚠️ Warning: When disassembling the router, be careful with antenna cables - they are attached to fragile connectors IPEX. Cable damage will cause loss of Wi-Fi signal.

If the router does not respond even to the serial console, the flash memory may be damaged, in which case the chip (for example, Winbond 25Q128JV) will need to be replaced with the CH341A programmer.

8.Set up router after flashing

After successful firmware OpenWRT or Padavan, perform the basic setup:

• 🌐 Change. IP-router address (by default 192.168.1.1 may conflict with other devices on the network). → LAN.
• 🔒 Set a new password for the web interface and SSH (OpenWRT: Passwd in the terminal).
• 📶 Set up Wi-Fi: For 5 GHz, select a channel in the 36-64 range (in Russia, channels 36-48 and 149-165) are allowed. 802.11r (Fast Roaming) if there are breaks in the connection.
• 🛡️ Update packages (for OpenWRT): opkg update & & opkg upgrade

Recommended packages for OpenWRT:

• 📦 luci-app-sqm – traffic optimization (elimines lags in online games).
• 📦 wireguard support VPN-WireGuard protocol.
• 📦 ddns-scripts - dynamic DNS accessing a router from the Internet.

💡

After flashing on OpenWRT, be sure to disable the dnsmasq service and install unbound to protect against the threat. DNS-Leaks (especially important when using the VPN).

FAQ: Frequent questions about Xiaomi Redmi flashing AC2100