ArubaInstant_6.5.4.20_82546 1
For more information on Aruba IAP-215 firmware downloads and updates, refer to the following resources: aruba iap 215 firmware download
Ensure you are downloading the "Instant" firmware and not the "Controller" (AOS) firmware. The IAP-215 runs Instant OS natively. While it can be converted to run as a Campus AP (controlled by a Mobility Controller), the file format for that is different. ArubaInstant_6