Huawei's Xinghe Intelligent Campus defines three standard 'Access Authentication' modes for users and terminals:

802.1X (B): High security, suitable for PCs and mobile devices with clients.

Portal (C): Common for guest access and public areas (web-based login).

MAC Address Authentication (A): Used primarily for 'dumb' terminals like printers, cameras, and IoT devices that cannot perform 802.1X/Portal logins.

OSPF Authentication (D) is a protocol-level security feature used to secure routing updates between routers, not an access authentication method for end-user devices.