I’m facing the following issue: I installed OpenWrt on my Ubiquiti U6+, and everything worked fine during initial testing. However, after relocating the device, I noticed that the Wi-Fi speed was significantly slower than expected (only 20 Mbps instead of the usual 150 Mbps). A restart didn’t resolve the issue. Since the LAN speed was fine, I suspected the problem was with the U6 itself.
I decided to update all packages, but after doing so, I was unable to access the LuCI interface. A further restart didn’t help. SSH access was still possible, but it displayed several errors.
Running out of options, I activated the U6’s recovery mode to perform a full reinstallation of OpenWrt. While enabling recovery mode was successful, I couldn’t establish a connection via TFTP despite several attempts and carefully following the official guide. Furthermore, I’m now stuck in recovery mode and can’t exit it.
My question is: What can I do to make the U6 operational again? Is there hope, and if so, what steps are necessary to resolve this issue?
I've never used recovery mode, maybe someone else can chime in.
According to wiki the router should be reachable via a link-local IPv6 address in recovery mode, if all else fails.
Have you tried running wireshark or tcpdump on a connected PC, power cycling the router, and see if it spits out some packets showing its IPv6 address?
Personally I have a $5 RS232<->USB adapter and I just plug that into the router and that gives you console access almost no matter how much you brick the software on it.
Update all packages is very likely to completely break the install. The OpenWrt design is not like a desktop where multiple versions of packages and libraries safely co-exist. The only safe way to update OpenWrt is to reinstall the whole OS.
To TFTP recover, you must use stock firmware since the recovery process requires a Ubiquiti signature on the firmware. Also the IP address of the recovery varies. If you have serial the signature won't be checked and you can work directly to TFTP boot OpenWrt to RAM then flash a sysupgrade image.
(The Lite and LR models are kind of similar, if you click those links at the top you may find some additional information that is more or less relevant too. Don't follow any firmware links for the wrong model though.)
The IPv6 link-local address is a generic thing, just like Windows usually has a 169.254.x.y address on an interface even if the IPv4 configuration is otherwise borked.
If finding and connecting to the IPv6 address is too much trouble, there is also a link on the U6+ wiki page to the Ubiquiti recovery instructions for that model.
By the way, on the subject of finding the correct wiki page.. What I usually do when installing on a new device is first figure out the openwrt model string ("unifi-6-plus" in this case) and google that ("unifi-6-plus openwrt wiki" minus quotes). Then I go to the wiki page, and head straight for the commit link. And read the commit message as the first thing, then go back and read the wiki.
Well, referring to "the official guide" as a description of what you did would be fine if it worked.... Are you asking us to assume that you read the correct guide and followed every step exactly as described? OK, I can do that. But it probably won't solve any issues.
And "stuck in recovery mode", what does that mean? The AP stays in recovery mode until you either tftp an image or pull the power. This is expected.
Note that the unifi recovery mode is completely independent of Openwrt and supported by ubiquity:
There's a section at the bottom titled "When Recovery Mode Doesn't Work". I've never experienced that myself, but it looks like it might happen. If so, then the procedure is documented there.
But we could try to figure out if there was something else going wrong first.
It’s stuck in Recovery Mode. Even after unplugging and restarting, it still boots into Recovery Mode. I followed the guide several times, but it didn’t work.
Yeah, I’ll give the Lite a try since it’s the closest to the Plus and seems simpler. I hope this will be the solution. I can only test it at the end of the day, as I’m currently at work.
Does this mean that you could still enter commands in SSH? If that's the case, the device was never bricked to begin with. Because being able to login via SSH requires a successful boot in the first place. It would also help if you told us what those "several errors" were.
Just to be clear, Unifi's recovery mode is meant to flash the official Unifi firmware, not third-party ones like OpenWrt. Download the official firmware from their site and TFTP that for recovery. Then attempt the OpenWrt install process from scratch as if it was a new device.
One quirk with the way the partitions are setup on U6+ is that TFTP recovery does not touch the partition OpenWrt stores the root filesystem. This enables some advanced rescue scenarios. But it also means it won't erase a damaged OpenWrt root.
If OpenWrt still doesn't work even after recovery and flashing, you might need to erase the kernel1 partition before flashing. But before you do this please check that the stock firmware boots and you can SSH as the ubnt user.
So, I did it—I flashed the original firmware onto it, and now it’s working. I had the same problem again, but this time I restored it via SSH and the firstboot argument , and after 5 minutes, I regained access to LuCI.
I followed this guide with the exact software, and it worked.
It actually wasn’t working. I just kept rebooting and checking, and it made a slight click when I pressed it.
Yes, I had access, and the server gave the excact same error 7-9 times after each command.
parse_from_stream_nomalloc: Missing new line character at end of file
I wasn’t able to solve that, so I thought recovery was the best option.
