This guide details how to to enable support for CoA / Disconnect Message on your UniFi controller. This is required in order to use the Tiered Bandwidth data cap and/or E-mail verification kick off feature.
Start by logging into your UniFi controller.
Browse to Settings > Guest Control on the left. Set the following:
Click Apply Changes to save.
IMPORTANT: CoA works by accepting inbound traffic from our RADIUS. We will send this request back to the same WAN IP of which your UniFi controller uses for outbound traffic to our RADIUS. Therefore, you will need to forward port 3799 (UDP) on your firewall from this WAN IP to the UniFi controller IP on your local network.