Question

1.) Your employer is opening a new location, and the IT director has assigned you the task of calculating the subnet numbers for the new LAN. You’ve determined that you need 10 subnets for the class C network beginning with the network ID 192.168.1.0. How many host bits will you need to use for network information in the new subnets?

2.) After the subnetting is complete, how many unused subnets will be waiting on hold for future expansion, and how many possible hosts can each subnet contain?

3.) What is the new subnet mask?

4.) What is the new CIDR notation?

Answer 1

Solution:

Given,

=>Network address prefix = 192.168.1.0

=>Number of subnets = 10

(1)

Explanation:

Calculating number of bits for subnetting:

=>Number of bits for subnetting = ceil(log₂(number of subnets))

=>Number of bits for subnetting = ceil(log₂(10))

=>Number of bits for subnetting = ceil(3.32)

=>Number of bits for subnetting = 4 bits

Calculating number of host bits:

=>As given network address is class C address and in class C, 24 bits are given to net ID part and 8 bits are given to host ID part.

=>As 4 bits are borrowed from host ID part for subnetting so rest 4 bits will be given to host ID part.

=>Hence number of bits for host ID = 4 bits

(2)

Explanation:

=>As with 4 bits number of subnet = 2^4 - 2

=>As with 4 bits number of subnet = 16 - 2

=>As with 4 bits number of subnet = 14 subnets

Calculating number of unused subnets:

=>Number of unused subnets = total subnets - subnet required

=>Number of unused subnets = 14 - 10

=>Number of unused subnets = 4 subnets

Calculating number of hosts in each subnet:

=>Number of hosts with 4 bits = 2^4 - 2

=>Number of hosts with 4 bits = 16 - 2

=>Number of hosts with 4 bits = 14 hosts

(3)

Explanation:

Calculating subnet mask:

=>Net ID bits + subnet ID bits = 24 bits + 4 bits

=>Net ID bits + subnet ID bits = 28 bits

=>Put all 1's in net ID and subnet ID and all 0's in host ID part to find the subnet mask.

=>Subnet mask = 11111111.11111111.11111111.11110000 in binary

=>Subnet mask = 255.255.255.240 in decimal

(4)

Explanation:

Calculating new CIDR notation:

=>Net ID bits + subnet ID bits = 24 bits + 4 bits

=>Number of host bits = 4 bits

=>New CIDR notation = 192.168.1.0/28

I have explained each and every part with the help of statements attached to it.