Hi Paniya,   This article helped us a lot: https://community.fortinet.com/t5/FortiAuthenticator/Technical-Tip-FortiAuthenticator-802-1x-EAP-TLS-with-computer/ta-p/212559   The Meraki AP (connected to a Cisco switch) was set as the RADIUS Client in FAC. We also had to use the Local Out Routing feature on the Fortigate, this makes sure that the Meraki AP IP address is used as the source IP and not each WiFi connected client seperately. ... View more