In the white list that you indicate, you mean the option "Add client", if that is it. The truth is, consult the support and they told me that you cannot delete the clients you add. You can change their policies so that you enable or block them. "But they cannot be erased" ... View more

You can add MAC addresses by going to Network-wide ==> Clients ==> Add Client, you can also choose a group policy if you required to have custom firewall rules, shaping etc.    However MAC address based restrictions are not the best thing to do as this can be easily spoofed. I would highly recommend looking in to deploying 802.1X with EAP-TLS or using Meraki MDM to manage and restrict the devices which will be using the SSID's. ... View more