16. What are two different types of DNS queries? 17 What are two types of HTTP connection? Which one has lower RTT (Round Trip Time) Delay? 18. What is the advantage of DNS Cache and HTTP Cache? 19. What is the role of IGMP in Multicast environment? 20. What is significance of all the host IDs set to 0 vs. all the host IDs set to 1? 21. Why do HTTP, FTP, SMTP, and POP3 run on the top of TCP rather than on UDP? 22. For a communication session between a pair of processes, which process is a client and which process is the server? 23. What are different parameters that are provided to client by a DHCP server besides IP address? 24. Is HTTP a Stateful or Stateless Protocol