单项选择题 What is the first 24 bits in a MAC address called?（）

单项选择题 What is known as "one-to-nearest" addressing in IPv6?（）

多项选择题 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? （）