（1）TCP/IP Addressing and Protocol
1: Your junior network administrator wants to know what the default subnet mask is for a Class C IP address. What do you tell him?
2: An application needs to have reliable, end-to-end connect-ivity. Which of the following protocols will give you reliable connectivity?
3: You are designing a network, which needs to support 55 users. You don't plan to extend the segment beyond the current number of users. Which subnet mask would best meet your needs?
4: You have added a new switch to your network. You want to manage it remotely, so you need to assign it an IP address. Your router that connects to the switch has an IP address of 172.16.12.33/27. Which of the following addresses can you assign to this switch?