Environment : This article applies to all Aruba controller running ArubaOS version 6.3 and above.
Sometime, while troubleshooting it becomes important to understand which tunnel in the group is active. The "Active Tunnel Id" column in the show command below, lets us know the active tunnel ID.
Once the active tunnel goes down, the second tunnel comes up automatically. The below screen show the tunnel# 2 going UP.
Tunnel Group also comes with a configuration of "Preemption", that allows the switching of tunnel once the first tunnel comes back up. Thus having a active tunnel all the time for the traffic to go through.