Environment : This article applies to all Instant Access Points (IAPs) running on any version of Aruba InstantOS
Aruba Instant does not require an external mobility controller to regulate and manage the Wi-Fi network. Instead, one IAP in every network assumes the role of a Virtual Controller (VC).
Virtual master will broadcast master heartbeat every second using custom Ether Type packet of 0x8ffd as shown in the below capture:
Other existing or new IAP's would listen to this heartbeat and becomes a member of the cluster. At any time, if a member IAP do not hear master beacon for a while, then it triggers the conflict resolve algorithm to compute a new master.
Note: Master heartbeat is also referred as Master Beacon.