802.1x authentication is mainly used in scenarios where the internal network is strictly controlled. The requirement in this scenario is that the internal network cannot be accessed (including Layer 2 networks) without authentication and cannot pass through Layer 2 switches. The advantage is to achieve strict network access control. If there is no authentication, the Layer 2 network cannot be accessed, preventing illegal users and endpoints from accessing the network, and they cannot access the intranet without authentication.

802.1x authentication has three modules: 802.1x Access Control, Switch Correlation, and VLAN User Group.