info_i_25x25.png See important information about Ubiquiti Devices and KRACK Vulnerability in this article. We will update this document as more information becomes available.

(Outdated) airMAX - How to reset your device with TFTP firmware recovery

Video Tutorial


If you already tried resetting your device to factory default values with the reset button and you can't access the unit, we recommend that you perform a TFTP recovery.

Note: TFTP recovery can be performed with almost any version of firmware. We recommend downloading the latest version for your model from



  • UBNT device to upgrade
  • A narrow tool to press down reset button (like the pin of a headset or paper clip)
  • An Ethernet cable
  • TFTP client running on PC
  • Latest airOS firmware file (you can download it from

Note: this guide refers to a PC running Windows, but is easly applicable to any other OS.


  • Do not switch off, do not reboot and do not disconnect the device from the power supply during the firmware upgrade process, as these actions will damage the device!

Recovery procedure 

Windows Users

  1. First, power off the device
  2. Configure your computer: Windows PC's Ethernet must be configured manually with the following settings (under Network Connections):
    IP Address:, Subnet Mask :
  3. Connect your radio to the PC
  4. Begin by pressing the reset button. Keep holding, then power the unit on. Wait 8 seconds then release the button (if you want to reset the unit to factory defaults, wait at least 15 seconds). Signal LEDs will be lit indicating that the device is ready for recovery
  5. Make sure that radio responds to pings (perform a ping from a DOS window), if it does not, go back to the first step

  6. Upload firmware image file .bin to, using a TFTP client software (binary mode). Windows integrated command line TFTP client or download a third party utility to upload the airOS firmware. Below are two examples:
    1. Windows Alternative 1: From Windows PC, you can use TFTP command line from a DOS window (START>>>CMD): 

    2. Go into the same directory structure as the firmware (e.g., assuming that you have stored the image files in c:\firmware directory, type the command :cd c:\firmware) and enter the following (for help type TFTP -h) , e.g.:

      tftp -i put XS2.ar2316.v3.4-rc.4351.090504.2146.bin

    3. Windows Alternative 2: Download and execute tftp2 and configure it as in the image to upgrade. 

  7. Signal LEDs will keep blinking one by one in 4 different colors during firmware upgrade. Wait for about 7-10 minutes (devices and firmware depending) - do not power off the device during the procedure!

Linux Users

Generic Linux distributions have an integrated command line TFTP client. From a PC running Linux, you can upload via TFTP by typing into Terminal the following commands:

tftp> bin
tftp> trace
tftp> put XS2.ar2316.v3.4-rc.4351.090504.2146.bin
Sent 1965199 bytes in 35.2 seconds 
tftp> exit

- UBNT-Salvador / UBNT-Kevin