单项选择题
Which term describes the process of encapsulating IPv6 packets inside IPv4 packets?（）
A. tunneling B. hashing C. routing D. NAT
单项选择题 What is the first 24 bits in a MAC address called?（）
单项选择题 When is it necessary to use a public IP address on a routing interface?（）
单项选择题 What will happen if a private IP address is assigned to a public interface connected to an ISP?（）
