1. Navigate to the Ubiquiti Downloads page to obtain the UniFi Controller firmware download link.
2. The latest UniFi Controller releases are listed in the Software section.
3. Expand the UniFi Network Controller for Debian/Ubuntu Linux and UniFi Cloud Key option and select download.
4. Accept the EULA and copy the firmware download URL. An example URL is:
https://dl.ui.com/unifi/x.xx.xx_version/unifi_sysvinit_all.deb
NOTE: You can also obtain the firmware link from the Ubiquiti Community Software Releases page.
Open the relevant UniFi Network Controller General or Beta release page and copy the UniFi Controller for Debian/Ubuntu and UniFi Cloud Key link.
5. Open a SSH session using your favorite SSH/Telnet client program.
NOTE: Access the Command Line Interface on the UCK (Unifi Cloud Key) using SSH.
See the Intro to Networking - How to Establish a Connection Using SSH article for more information on how to connect to the Cloud Key using SSH.
6. Navigate to the /tmp directory:
cd /tmp
7. Verify if there are any previous installation files present in the directory and delete them if applicable:
ls -l
rm unifi_sysvinit_all.deb
8. Use the wget command with the previously copied link to download the UniFi Controller installation file and store it in the /tmp directory.
9. Replace https://dl.ui.com/unifi/x.xx.xx_version/unifi_sysvinit_all.deb with the previously copied URL.
wget https://dl.ui.com/unifi/x.xx.xx_version/unifi_sysvinit_all.deb
10. Wait for the firmware download process to complete and install the new version using the dpkg command:
sudo dpkg -i unifi_sysvinit_all.deb
NOTE: If the UniFi Controller version needs to be downgraded to an older release, then the currently installed version can be removed with the
sudo dpkg -P unifi
command.
11. Wait for the installation process to complete and remove the unifi_sysvinit_all.deb file afterwards.
rm unifi_sysvinit_all.deb