Environment : This article applies to Instant Access Points being managed by Aruba Central.
Instant Clusters being managed by Aruba Central are actually deployed behind firewall at different customer locations. Initiating an external connection is not possible to the Virtual Controller of the Instant clusters.
Instead virtual controllers of each cluster that are being managed by Central, send heartbeat to Aruba Central. Thereby, Central in response to these heartbeats sends an acknowledgement appending the configuration changes made. As these exchanges happen on well-known HTTPS protocol, there is no need of opening any ports on firewall at various customer setups
So, when the configuration changes are huge, they append the changes little by little to every acknowledgement message. In the meanwhile, till the device sync gets completed, the Virtual Controllers show exclamation symbol on them. As shown in the image below: