Installing OpenWrt on MX4200

Guide was followed at certain parts here https://openwrt.org/toh/linksys/mx4200_v1_and_v2

Overview

Hardware

Linksys AX4200 Velop Mesh Wi-Fi 6 System It was a steal! !

Software

I chose OpenWrt… Why? Default router firmware typically lacks advanced features, security updates, and general support that OpenWrt provides. What else? It’s OPEN SOURCE!

Downloading OpenWrt

• We need to select the proper firmware for our device.
• Go to https://firmware-selector.openwrt.org/ and search for mx4200!
• I had no clue if I had v1 or v2, this link cleared it up https://www.reddit.com/r/LinksysVelop/comments/1655uxh/mx4200_v1_vs_v2_difference/ (Model number for MX4200 V2 would just be MX4200V2)
• I chose Factory because I will be using the web interface to install the new firmware.

Flashing OpenWrt

• Connect your computer to your MX4200 via ethernet and enter 192.168.1.1 into your browser and hit enter.
• Click on the wifi icon to unlock the secret menu !
• You may have to reset password here, I tried the default password and it didn’t work. Enter the password and sign in.!
• Click Connectivity on the left.!
• Click on the CA on the bottom-right!
• Click Choose File > choose your openWrt file > click Start!
• Click YES!!
• Click YES!!!
• Wait for the firmware to flash!
• The device will reboot after a few minutes and the LED on the router will be solid blue. BE PATIENT. !
• Once the light is solid blue it’s done!

Flash OpenWrt to Alternate Boot Partition

MX4200 routers use two firmware partitions. If you do a 30/30/30 reboot (press reset button for 30s. While holding, unplug router for 30s, power on, hold the reset button for 30 more seconds) the device then it will boot to the alternate partition. You can do the same thing to swap back to the primary partition.

• SSH into OpenWrt using PuTTY or other SSH client!
• If prompted for a certificate > click Accept
• Login as: root > hit enter!
• Run command fw_printenv -n boot_part. This is the partition we are currently booted into.!
• SCP (I’m using WinSCP) into OpenWrt > if prompted to accept a host key click Accept!!
• We’re now connected to OpenWrt through SCP!
• Navigate to /tmp/ by clicking .. > tmp !
• Copy your OpenWrt .bin firmware file into this tmp directory!
• Run the command cd /tmp/ !
• If you booted into partition 1 run the following command in the ssh client. Change version as required & modify V1 or V2!!! mtd -r -e alt_kernel -n write openwrt-24(.X.X)-qualcommax-ipq807x-linksys_mx4200v(X)-squashfs-factory.bin alt_kernel
• If you booted into partition 2 run the following command in the ssh client. Change version as required & modify V1 or V2!!! Note the difference in kernel vs alt_kernel. mtd -r -e kernel -n write openwrt-24.(.X.X)-qualcommax-ipq807x-linksys_mx4200v(X)-squashfs-factory.bin kernel
• Since I booted into partition 2 I ran the second command!
• After running the command the router will reboot and your ssh session will disconnect!
• Refreshing the web page with OpenWrt will open it again!

Configuring OpenWrt

• Once the router is flashed, go to 192.168.1.1!
• Username is root > no password > Log in !
• Go to Network > Wireless. Our 5GHz adapter is 802.11ac..., our 2.4GHz adapter is 802.11ax.!
• Click Edit on the first SSID!
• On this page change the following:
  • Channel: auto
  • Width: 80MHz (160 isn’t supported)
  • Country Code: US - United States
  • ESSID: OpenWrt5
• Under Wireless Security change the following:
  • Encryption: WPA2-PSK (strong security)
  • Key: Set your password for the wifi
• Click Save & Apply and we should have wifi!