https://www.arubanetworks.com/techdocs/AOS-CX/AOSCX-CLI-Bank/cli_6300-6400/Content/Chp_Port_acc/Port_acc_rol_cmds/aut-mod-fl-10.htm client-mode = Selects client mode. In this mode, all clients connecting to the port are sent for authentication.
device-mode = Selects device mode. In this mode, only the first client connecting to the port is sent for authentication. Once this client is authenticated, the port is considered as open and all subsequent clients trying to connect on that port are not sent for authentication.