Question $15$

$($i$)$ Give a brief description of ICMPv$6$ and how it differs from ICMPv$4.$

$($ii$)$ IPv$6$ does not use ARP. Which protocol is used in IPv$6$ to determine MAC

address of the destination host?

$($iii$)$ Explain what is a purpose of DNS$?$ What are the Iterative and Recursive Name

Resolution protocols? How are the DNS packets transmitted? Imagine a situation

when all DNS servers in the world would crash simultaneously. Would it be still

possible in principle to use the Internet? If yes, what the users would need to know to

continue using the Internet? If no$,$ explain why. What is the maximum allowed length

of the full domain name in the DNS resource record?