- Subnet D - 125 Hosts
- Subnet C - 47 Hosts
- Subnet B - 6 Hosts
- Subnet A - 2 Hosts
Step1: Begin with SubnetD as it requires the most number for hosts.
We are given the Network Address in the question and the First host is always Network +1 (N+1).
To find the Subnet mask we need to look at how many bits need to be used to create a network that will have at least 125 hosts. To find this we use 2^n where n= the number of bits used in the subnet mask.
From the table you can see we need to borrow 7 bits from the host portion of the subnet mask to create a subnet that will use at least 125 hosts. In this case borrowing 7 bits will give us 128 addresses but we lose 2. One for the network and one for broadcast leaving us with 126 addresses for Hosts.
If the Subnet Mask has 32 bits and we use 7 of them for the host portion, this means 25 bits remain as subnet bits in the subnet mask. This subnet mask can be represented by /25, where this means the first 25 bits off the subnet mask are all 1’s.
Broadcast address is your network address plus 128 addresses and the last use-able host in one less than that (BC-1). From here you can work out the following table:
Use this method for Subnet A,B and C, going from the subnet with the most number of hosts to least number of hosts until you come to the following:
