$1.$ An organization is granted the block $211\mathrm{.}17\mathrm{.}180\mathrm{.}0/24.$ The administrator wants to create $32$ subnets.

a$.$ Find the subnet mask.

b$.$ Find the number of addresses in each subnet.

c$.$ Find the first and the last address in the first subnet.

d$.$ Find the first and the last address in the last subnet $($subnet $32).$

$2.$ Find the range of addresses in the following blocks:

a$.123\mathrm{.}56\mathrm{.}77\mathrm{.}32/29$

b$.200\mathrm{.}17\mathrm{.}21\mathrm{.}128/27$

c$.17\mathrm{.}34\mathrm{.}16\mathrm{.}0/23$

d$.180\mathrm{.}3464\mathrm{.}64/30$

$3.$ In classless addressing, we know the first address and the number of addresses in the block. Can we find the prefix length? If the answer is yes, show the process and give an example.

$4.$ An ISP is granted a block of addresses starting with $150\mathrm{.}80\mathrm{.}0\mathrm{.}0/16.$ The ISP wants to distribute these blocks to $2600$ customers as follows:

a$.$ The first group has $200$ medium$-$size businesses; each needs approximately $128$ addresses.

b$.$ The second group has $400$ small$$ businesses;$$ each$$ needs$$ approximately $16$ addresses.

c$.$ The third group has $2000$ households; each needs $4$ addresses.

Design the subblocks and give the slash notation for each subblock. Find out how many addresses are still available after these allocations.

$5.$ An ISP is granted a block of addresses starting with $120\mathrm{.}60\mathrm{.}4\mathrm{.}0/20.$ The ISP wants to distribute these blocks to $100$ organizations with each organization receiving $8$ addresses only. Design the subblocks and give the slash notation for each subblock. Find out how many addresses are still available after these allocations.

$6.$ An ISP bas a block of $1024$ addresses. It needs to divide the addresses to $1024$ customers. Does it need subnetting? Explain your answer..