What is the typical size of the header for an IPv$4$ datagram? $[1]$

b$.$ How is the $16-$bit IP checksum field calculated? $[2]$

c$.$ How is the TTL field used on the Internet? What purpose does it serve? $[2]$

d$.$ Which field is used for IP congestion control? How does it work? $[2]$

e$.$ Why is datagram fragmentation not an issue in IPv$6?$ How is this achieved? $[2]$

f$.$ A message of $2300$ bytes is to be transmitted over $2$ IP networks. The first has an MTU of

$2300$ bytes and the second network has an MTU of $1500$ bytes. How many fragments are

expected at the destination? Show the values of the following IP header fields and flags

for each fragment on the two networks: Packet length, MF$,$ Fragment Offset and

Identification. $[7]$

g$.$ What does ICMP stand for? Briefly explain the key areas of functionality for ICMP giving

an example. $[3]$

h$.$ Convert the MAC address CC$-12-$DE$-4$A$-$BD$-88$ into the corresponding binary digits. $[3]$

i$.$ Given the following subnet masks determine the number of a$)$ host bits available and b$)$

the number hosts available. $[3]$

i$.255\mathrm{.}255\mathrm{.}240\mathrm{.}0$

ii$.255\mathrm{.}255\mathrm{.}255\mathrm{.}0$

iii. $255\mathrm{.}255\mathrm{.}255\mathrm{.}128$