Hi, i can see 2 possibilities   * There is a feature request on ISE: Enhancement request for Cisco ISE to send RADIUS accounting messages (CSCvd83297) to Fortigate   * Preferred solution: Feature request to send duplicate radius accounting messages f...

Hi Joris, I recently learned that 3850 is going to support REP in release 16.2.1 It will be available in the coming months. We are also waiting on it... An alternative that you could consider  today is 2960XR. I believe it also has all the features...