填空题 1.  ______ is an IEEE standard that provides a framework for authenticating and authorizing network devices connected to LAN ports and for preventing access in the event that the authentication fails. ______标准是一种基于端口的访问控制架构，它对连接到局域网端口的设备进行认证与授权，确保只有合法用户才能访问网络资源与服务。