Consider sending a $4000$ byte datagram into a link that has an MTU of $1220$ bytes. Suppose the

original datagram is stamped with the identification number $321.$ How many fragments are

generated $($there may be extra lines...$)?$

a$)(40)$ Show the values of all relevant IP fields in each fragment.

b$)(40)$ Some programs are particularly sensitive to fragmentation. Sketch an idea for how one

might find the minimum MTU on a path through the Internet. One may assume:

a$.$ A maximum MTU is $1500B$

b$.$ The path through a fixed sequence of routers a packet may go through is fixed while you

are finding the minimum MTU.

c$.$ You do not need to know the link that actually has the minimum MTU.

d$.$ A packet may be marked $"$Do not Fragment". If such a packet is too large for an

outbound link, it will be dropped. $4$

e$.$ The MTU is only generally known for networks a device has interface in; to be clear,

your computer only knows the MTU for the network$($s$)$ connected to$,$ normally.