As I understand it, 802.11i WPA2 mandates exactly AES128.   I believe WPA3 802.11ax mandates AES192.   To get to AES256 you need a solution that supports Suite-B, such as a Cisco WLC solution.  Note that Suite-B while still in common use is no longer considered secure for the long term due to quantum computing.   I'm thinking that if you have a specific need for Suite-B that Meraki is probably not the correct choice for you, as you probably have some other requirements as well.   Also note you will need Suite-B compliant WiFi clients. ... View more