Unifi USG recover and upgrade

When your USG fails and replacement or re-image of the USB is necessary, follow these steps

• Remove USB stick from USG by removing the screws under the rubber feet.
• Download the original image
  • https://dl.ubnt-ut.com/cmb/USG-4_2_0-shipped.img.bz2
• Use Blena Etcher to flash file onto the USB stick
• Replace USB stick and close up USG
• Power USG and get workstation on LAN with WAN connected to internet
• SSH into USG at 192.168.1.1
  • ubnt:ubnt
• The next step is using SCP to copy from workstation to USG- Skip to the next section to use “curl” on console
• Download firmware to your workstation
  • look for desired version
    • https://www.ui.com/download/software/usg
    • I’ll usually update in steps, I do not know how many revisions one can skip
  • scp path/to/file ubnt@192.168.1.1:/home/ubnt/upgrade<version>.tar
• On console use curl to copy firmware
  • curl -o upgrade<version>.tar https://dl.ubnt.com/path/to/version/desired
• Initiate upgrade
  • sudo syswrapper.sh upgrade upgrade<version>.tar