Problem 5. DNS Query (2pts) Consider a network with a local DNS caching resolver and a set of authoritative DNS name servers. There are no packet losses, .edu zone has the following records: RTT between stub resolver and caching o edu. NS ns.edu. resolver is 10ms, o ns.edu. A 3.3.3.3 RTT between caching and any O fiu.edu. NS ns.fiu.edu. authoritative resolver is 100ms o ns.fiu.edu. A 4.4.4.4 Initially, the caching resolver cache is fiu.edu zone has the following records: empty o fiu.edu. NS ns.fiu.edu. TTL values for all records are 1 hour. o ns.fiu.edu. A 4.4.4.4 Caching DNS resolver IP: 1.1.1.1 www.fiu.edu. A 5.5.5.5 Authoritative for "root" zone: 2.2.2.2 O fiu.edu. A 5.5.5.5 a) At T=0 min, client's stub resolver wants to obtain IP address for "www.fiu.edu". How long it will take to resolve this query? Show the time and HOW you obtained the value (i.e., which queries have been sent by whom) b) At T=30 min, the same client asks for IP address for "fiu.edu" (without www). How long it will take this time? Again, show the time and HOW you obtained the value. c) At T=70 min, select all records that not yet expired in the caching resolver edu. NS ns.edu. O ns.fiu.edu. A Ons.edu. A 3.3.3.3 www.fiu.edu. A fiu.edu, NS ns.fiu.edu. fiu.edu. A 4.4.4.4 5.5.5.5 5.5.5.5 Problem 5. DNS Query (2pts) Consider a network with a local DNS caching resolver and a set of authoritative DNS name servers. There are no packet losses, .edu zone has the following records: RTT between stub resolver and caching o edu. NS ns.edu. resolver is 10ms, o ns.edu. A 3.3.3.3 RTT between caching and any O fiu.edu. NS ns.fiu.edu. authoritative resolver is 100ms o ns.fiu.edu. A 4.4.4.4 Initially, the caching resolver cache is fiu.edu zone has the following records: empty o fiu.edu. NS ns.fiu.edu. TTL values for all records are 1 hour. o ns.fiu.edu. A 4.4.4.4 Caching DNS resolver IP: 1.1.1.1 www.fiu.edu. A 5.5.5.5 Authoritative for "root" zone: 2.2.2.2 O fiu.edu. A 5.5.5.5 a) At T=0 min, client's stub resolver wants to obtain IP address for "www.fiu.edu". How long it will take to resolve this query? Show the time and HOW you obtained the value (i.e., which queries have been sent by whom) b) At T=30 min, the same client asks for IP address for "fiu.edu" (without www). How long it will take this time? Again, show the time and HOW you obtained the value. c) At T=70 min, select all records that not yet expired in the caching resolver edu. NS ns.edu. O ns.fiu.edu. A Ons.edu. A 3.3.3.3 www.fiu.edu. A fiu.edu, NS ns.fiu.edu. fiu.edu. A 4.4.4.4 5.5.5.5 5.5.5.5