Q $1.$ a$)$ The default gateway's IP address in a network is assigned to be $109\mathrm{.}0\mathrm{.}8\mathrm{.}253.$ The network can $4$ CO$1$ support about $2045$ devices after assigning the above IP$.$

I. Identify the subnet mask and the broadcast address of the given network.

II$.$ State the host size of the given network.

b$)$ Using the network address found in $(1.$a$.$I$),$ calculate the subnet addresses that will create the

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minimum amount of waste for the following host requirements: a WAN link and a switched network connected to $4$ routers, LANs of size $500$ and $255$ hosts.

Q $2.$ a$)$ In "Traceroute" application, the originator sends the first packet with TTL$=1$ and $CO2$ continuously increments it and resends the packet. How does it know that the packet has reached the destination, that is$,$ how does it know when to stop?

b$)$ You receive a packet whose data length is $900$ bytes, ID is $2398$ and the MF flag is set to $0.$

$4$

You received the remaining $12$ packets, each of whose total length is $1945$ bytes, ID is $2398$ and the MF flag is set to $1.$ All of these packets' header size is $25$ bytes.

I. Find the packet size of the original datagram

II$.$ Find the value of the offset field of the $2$ nd last packet $[$First data byte number starts at $0]$

III. How would you identify the last packet in a group of fragmented packets?

c$)$

$4$

$+$

$+$

$2$

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$4$

$+$

$+$

$2$

$($e$)$

State why BRACU Router is unable to send this packet through the Internet. And what will be the solution to this problem, especially when the internal network connected to BRACU router has $500$ hosts.