MAC authentication
The MAC authentication method grants access to a secure network by authenticating devices for access to the network. When a device connects to the switch, either by direct link or through the network, the switch forwards the device's MAC address to the RADIUS server for authentication. The RADIUS server uses the device MAC address as the username and password, and grants or denies network access in the same way that it does for clients capable of interactive logons. The process does not use either a client device configuration or a logon session. MAC authentication is well-suited for clients not capable of providing interactive logons, such as telephones, printers, and wireless access points. Also, because most RADIUS servers allow for authentication to depend on the source switch and port through which the client connects to the network, you can use MAC authentication to "lock" a particular device to a specific switch and port.
802.1X port-access, web-based authentication, and MAC authentication can be configured at the same time on the same port. The client limit is 32 clients per port for MAC-auth and Web-auth; the client limit for 802.1X is 32 clients per port. The MAC-auth and Web-auth limit of 32 clients only applies when there are fewer than 16,384 authentication clients on the entire switch. After the limit of 16,384 clients is reached, no additional authentication clients are allowed on any port for any method. The default is one client.
Web-based and/or MAC authentication and MAC lockdown, MAC lockout, and port-security are mutually exclusive on a given port. If you configure any of these authentication methods on a port, you must disable LACP on the port.