a. If the IP header length field’s value is 6 and the total length field’s value is 50, how long is the data field? Show your work. b. What is the general function of the second row in the IPv4...

a. If the IP header length field’s value is 6 and the total length field’s value is 50, how long is the data field? Show your work. b. What is the general function of the second row in the IPv4 header? c. Why is a TTL field needed? d. If a router receives a packet with a TTL value of 1, what will it do? e. What does the protocol field in the IP header tell the destination host? f. How is the header checksum field used? g. Are IPv4 options used frequently? h. Why is fragmentation a threat indication? i. How can attackers use the TTL field to map a network?