This is the explanation of one of the subnetting questios The network administrator is asked to configure 113 point-to-point links. Which IP addressing scheme best defines the address range and subnet mask that meet the requirement and waste the fewest subnet and host addresses?

The network administrator is asked to configure 113 point-to-point links. Which IP addressing
scheme best defines the address range and subnet mask that meet the requirement and waste
the fewest subnet and host addresses?

A. 10.10.0.0/18 subnetted with mask 255.255.255.252
B. 10.10.0.0/25 subnetted with mask 255.255.255.252
C. 10.10.0.0/24 subnetted with mask 255.255.255.252
D. 10.10.0.0/23 subnetted with mask 255.255.255.252
E. 10.10.0.0/16 subnetted with mask 255.255.255.252

Ans-D

solution- A- /18 is subnetted with .252 means /30 i.e-- total on bits will be 30-18=12 so subnets will be 2^12= 4096
B- /25 is subnetted  with /30 i.e.-- total on bits 30-25=5. so subnets will be 2^5=32
C- /24 is subnetted with /30 i.e.-- total on bits 30-24=6. so subnets will be 2^6=64
D- /23 is subnetted with /30 i.e-- total on bits 30-23=7. so subnets will be 2^7=128
E- /16 is subnetted with /30 i.e-- total on bits 30-16=14. so subnets will be 2^14=16384


Conclusion from all the options is -- for 113 subnets the best suited subnet is  /23 subnetted with /30 in which 128 subnets can be connnected. In this subnet there will be less wastage of sub Networks i.e only 128-113=15.