Can't Get OpenWrt Working (LUCI, SSH, WinSCP) on Ubiquiti AC AP Pro

Hello there—I'm a fairly novice (~6mos) OpenWRT user, previously on a WRT3200ACM, now looking to extend my network with some dumb access points. I thought I'd pick up a UAP AC Pro and flash it to OpenWRT, set it to act as an access point, and be on my way.

After following the instructions here (there are many, and they also differ from those on the UAP AC Pro hardware page itself), the device is bricked.

That is, can't make a Putty / WinSCP connection at all at the IP. The LUCI dialogue of course does not show up, either.

  • I downgraded the firmware to 3.7.58. The SSH command line was properly showing this after it was done.
  • I then flashed the sysupgrade OpenWRT firmware for the Unifi AP Pro to kernel 0
  • I erased kernel1
  • I write a single 0-byte in bs: dd if=/dev/zero of=/dev/mtd4 bs=1 count=1

Now that I look again.. I'm realizing I might have chosen the wrong firmware, as there are multiple listings for this device.


The name of my firmware image was openwrt-19.07.6-ar71xx-generic-ubnt-uap-pro-squashfs-sysupgrade.bin, which seems right though? Did I want the ath79 generic instead?

Am I headed for the Generic Debricking Guide?

You apparently mixed up and, which is not good…

While I'm not familiar with Ubiquiti devices, you will most likely need tftp to (maybe…) recover the device, if you can, serial console access would be beneficial.


Whew! I've managed to figure out restoring it by using TFTP and PumpKIN, going back to the proper Ubiquiti firmware and then flashing OpenWRT. No need to open the device up or use the serial cable, thankfully.

The device has rebooted and boots into a blue light state now. Unfortunately, I'm still not sure of how to connect to the device over SSH (if the IP it's been assigned is—shouldn't I be able to point PuTTY to it and have it connect if it's properly running OpenWRT?)

This access point is connected to one of my router's ports so it's understandable that it wouldn't be able to set up shop at, as that's already being taken.

Unsure of what to do next to verify that OpenWRT is running correctly TBH. Never done it in this sort of a daisy chain situation. Thoughts?

Arent you supposed to start a firmware conversion with the “install” firmware!?
You have started according to your post with a sysupgrade firmware and that only works when OpenWRT is already installed.

I would think so too, but the instructions mention the sysupgrade.bin, and in fact, for the ath79 chipset, there isn’t even a factory .bin. I’ll try it with one tomorrow and see how it goes, now that I know I can reliably get it back to its original firmware with TFTP.

sysupgrade.bin is the correct image for upgrading the Unifi AP AC Pro to OpenWrt.

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In a scenario where an OpenWRT device is sitting downstream from another router, i.e. being assigned an IP on the local network, is it expected that you should be able to SSH into it at the listed IP after an installation?

I'm not very well versed in some networking basics and have been hacking my way through OpenWRT for the last couple of months. So, I don't really know what a new OpenWRT device should be 'trying to do' or 'where it should be reachable' if it can't claim the IP address, if that makes sense.

From visual indicators (the lights on the UAP AC Pro) it seems like these installs are going successfully, but I'm not sure of how to check or access the device post flash.

That depends entirely on how you set it up…

If you use its WAN port to connect to your uplink, then the WAN firewall rules apply - rejecting any incoming connection.

If you use a LAN port AND disable DHCP/ DHCP-v6 (RA) AND properly configure this LAN connection (either static IP, with gateway and broadcast addresses set correctly XOR DHCP-client), see e.g., then the LAN access rules apply (access allowed).

On single ethernet port devices, OpenWrt defaults to use it as LAN port.

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Okay, I'm getting closer (only attending to this when I have spare time).

By changing my primary router's Luci IP to something else (, that freed up the ability to connect to the AP AP Pro via SSH at the OpenWRT default of So I can confirm it's installed.

From here the goal is to get it set up as a dumb AP. My first goal was to get luci-ssl up and running on the AC AP Pro so that I could easily configure that. So, I SSH into it—and opkg update gives the following errors:

Downloading                                                                                             packages/Packages.gz
Failed to send request: Operation not permitted
*** Failed to download the package list from

I'm not sure why my primary router doesn't seem to be granting downstream internet access to this thing, but I suspect it's expected. Attempting to ping different domains from it doesn't work either.

So perhaps my best bet is to try to configure it as a dumb AP from the command line, e.g. follow these instructions? I'm unsure of whether this device would be considered switchless etc. so I'm a bit nervous about proceeding.

The AP AC Pro has a secondary port on the back for one additional network connection. Predictably, feeding POE into that has no effect.

If anyone's got suggestions, I'm all ears.

Nevermind, all closed. All I needed to do was add

option gateway ''
list dns ''
option broadcast ''

To the lan interface within the /etc/network file so that it could properly pull DNS from the router it was plugged into. From there, the documentation was enough!

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