Redid my Ubiquiti setup at home, running the Controller inside a Docker container running on a Synology NAS. Problem is, the NAS is internet-exposed, and runs on a DMZ network, whereas the Ubiquiti Switches & APs are on the LAN.

I first tried to address this via by using the Firewall to forward ports (tcp/8080, etc) from the LAN to the Synology IP, but had no luck. Creating a DNS entry for ‘unifi.<MY_INTERNAL_DOMAIN>’ only worked half the time.

Then found it’s possible to explicitly set the IP of the controller. Here’s how:

1) If device SSH username & password is not known, perform a factory reset.

2) After the device comes back online, find the IP address, then SSH to the device with default username and password of ubnt/ubnt

3) At the Command Prompt, enter the IP address or FQDN of the controller

set-inform http://192.0.2.23:8080/inform

Within a few seconds, the device should show up as ready to be adopted.

Thanks to this post for reminding me of the command.