Environment : This applies to Aruba Instant Access Point starting from 184.108.40.206-4.0 release.
An IPsec tunnel is configured to ensure that the data flow between the networks is encrypted. When configured, the IPSec tunnel to the controller secures corporate data.
Starting from 220.127.116.11-4.0 release, Instant allows you to enable automatic configuration of the GRE tunnel from an IAP to Aruba Mobility Controller. By using an IPsec connection, the IAPs can now set up a GRE tunnel with the controller. This feature eliminates the need for the manual configuration of tunnel interface on the controller.
Following figures from IAP web interface show us the configuration:
NOTE: Initially, the dialogue box may look like the one shown above. But, as you starting mentioning the Primary and Backup host, additional settings would appear: