Subnetting Questions 12 | Find the number of Subnets from Subnet Mask

Subnetting Questions 12

On a class C network with a subnet mask of 192, how many subnets are available?

A/Q the value of the 4th octet is 192 and it is a Class C Address.

Therefore, the subnet mask is

255.255.255.192

(2⁷ + 2⁶ + 2⁵ + 2⁴ + 2³ + 2² + 2¹ + 2⁰) . (2⁷ + 2⁶ + 2⁵ + 2⁴ + 2³ + 2² + 2¹ + 2⁰) . (2⁷ + 2⁶ + 2⁵ + 2⁴ + 2³ + 2² + 2¹ + 2⁰) . (2⁷ + 2⁶)

11111111 . 11111111 . 11111111 . 11000000

Hence, we have borrowed 2 bits from the fourth octet (2⁷ + 2⁶ = 192)

Let’s find the number of subnet

2ⁿ (n is the number of borrowed network bits)

2² = 4

Therefore the number of available subnet is 4.