Ubiquiti supports multi-site management on the second generation Cloud Key models (UCKG2 and UCKG2+) as well as on self hosted UniFi Controllers, which includes HostiFi. Multi-site doesn't work on the first generation Cloud Key.
In this guide, we'll cover how to enable multi-site on a Cloud Key, why you should and why you might not want to.
⚠️ It is worth noting that the UDM, UDM SE, UDR and UDM Pro can only run one site per device.
How to enable multi-site on a Cloud Key
First, log into the Network Application on your Cloud Key and go to 'Settings'
Next, go to 'System'
Next, enable 'Multi-Site management', then click 'Apply Changes'
Once completed, a new site switcher will appear in the top left hand corner
When to use multi-site on a Cloud Key
While the Cloud Key offers an easy way to have local controller, and it supports multi-site - it might not be the best device to manage multipole UniFi sites, due to its very limited device capacity. To get remote devices adopted, it is most likely to require dynamic DNS or a public static IP address for the remote L3 adoption to work.
However, if you have a strict budget and a handful of sites with one or two APs and switches at each location, then the Cloud Key would be able to handle it.
However, when using the Cloud Key for UniFi Protect etc, this can only be run on the device and cannot be moved to a self hosted server, or HostiFi.
When to move to HostiFi
With the Cloud Key products, Ubiquiti does have some recommend limits. While there isn't an actual hard limit for how many devices the UCK can handle, there are some guidelines that Ubiquiti has published, it also takes into account the amount of concurrently connected clients.
Below are those recommendations
Cloud Key Gen 1
Cloud Key Gen 2
Cloud Key Gen 2 Plus
Cameras (UniFi Protect Only)
Cameras (UniFi Protect & UniFi Network)
If your deployment needs more devices than this, with more sites, more APs and more connected clients, then you have outgrown the Cloud Key. It becomes a better and more stable option to use UniFI Network self hosted, or use something like HostiFi - which can scale to meet your needs.
If you notice your Cloud Key is slowing down loading stats, then grab a backup file before it totally crashes. This file can be imported into HostiFi for a seamless transfer.