Question 3 (1 point) 2.4-4 DNS in Action (1). Suppose that the local DNS server caches all information coming in from all root, TLD, and authoritative DNS servers for 20 time units. (Thus, for example, when a root server returns the name and address of a TLD server for .com, the cache remembers that this is the TLD server to use to resolve a .com name). Assume also that the local cache is initially empty, that iterative DNS queries are always used, that DNS requests are just for name-to-IP-address translation, that 1 time unit is needed for each server-to-server or host-to-server (one way) request or response, and that there is only one authoritative name server (each) for any .edu or .com domain. Consider the following DNS requests, made by the local host at the given times: - t=0, the local host requests that the name gaia.cs.umass.edu be resolved to an IP address. - t=1, the local host requests that the name icann.org be resolved to an IP address. - t=5, the local host requests that the name cs.umd.edu be resolved to an IP address. (Hint: be careful!) - t=10, the local host again requests that the name gaia.cs.umass.edu be resolved to an IP address. Consider the following DNS requests, made by the local host at the given times: - t=0, the local host requests that the name gaia.cs.umass.edu be resolved to an IP address. - t=1, the local host requests that the name icann.org be resolved to an IP address. - t=5, the local host requests that the name cs.umd.edu be resolved to an IP address. (Hint: be careful!) - t=10, the local host again requests that the name gaia.cs.umass.edu be resolved to an IP address. - t=12, the local host requests that the name cs.mit.edu be resolved to an IP address. - t=30, the local host again requests that the name gaia.cs.umass.edu be resolved to an IP address. (Hint: be careful!) Which of the requests require 8 time units to be resolved? The request at t=0. The request at t=1. The request at t=5. The request at t=10. The request at t=12. The request at t=30