3. In this problem, we use the useful dig tool available on Unix and Linux hosts to explore the hierarchy of DNS servers. Recall that a DNS server in the DNS

hierarchy delegates a DNS query to a DNS server lower in the hierarchy, by sending back to the DNS client the name of that lower-level DNS server. First read the man page for dig, and then answer the question: starting with a root DNS server (from one of the root servers [a-m].root- servers.net), initiate a sequence of queries for the IP address for google.com by using dig. Show the list of names of DNS servers in the delegation chain in answering your query. 4. UDP and TCP checksum.