问题：

[多选]

Refer to the exhibit.A junior network administrator was given the task of configuring port security on SwitchA to allow only PC_A to access the switched network through port fa0/1. If any other device is detected， the port is to drop frames from this device. The administrator configured the interface and tested it with successful pings from PC_A to RouterA， and then observes the output from these two show commands. Which two of these changes are necessary for SwitchA to meet the requirements？（）

A . Port security needs to be globally enabled.
B . Port security needs to be enabled on the interface.
C . Port security needs to be configured to shut down the interface in the event of a violation.
D . Port security needs to be configured to allow only one learned MAC address.
E . Port security interface counters need to be cleared before using the show command.
F . The port security configuration needs to be saved to NVRAM before it can become active.