====== Ubiquiti - CLI - Upgrade Controller ======
1. Navigate to the Ubiquiti [[https://www.ui.com/download/unifi/|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 [[https://community.ui.com/releases|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
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===== References =====
https://help.ui.com/hc/en-us/articles/216655518-UniFi-UDM-UCK-How-to-Change-the-Controller-Version-Using-SSH-