You are deploying Aruba CX 6300's with the customers requirement to only allow one (1)...

Aruba CX 6300 switches support various features to control the port access for different types of devices, such as client mode, device mode, and multidomain mode. These features can help limit the number of clients that can connect to a port and prevent unauthorized devices from accessing the network.

This is because option C shows how to configure the client limit and the auth-mode for a specific port using the interface command and the aaa authentication port-access command. The client limit specifies the maximum number of clients that can connect to a port. The auth-mode specifies the authentication mode for the port. In this case, option C sets both parameters to multi-domain mode, which allows only one voice device and one data device to be authenticated on a port

https://www.arubanetworks.com/techdocs/AOS-CX/10.10/HTML/monitoring_6300-6400/Content/Chp_LEDs/fro-pan-led-630.htm  2: https://www.arubanetworks.com/products/switches/6300-series/  3: https://www.arubanetworks.com/techdocs/AOS-CX/10.11/HTML/security_6200-6300-6400/Content/Chp_Port_acc/Port_acc_gen_cmds/aaa-aut-por-acc-aut-mod-fl-109.htm