Subnetting Questions 23 | Find the CIDR Value from the subnet mask

Subnetting Questions 23

What is the shorthand corresponding to a subnet mask of 255.255.255.240?

or

Find the CIDR Value from the subnet mask 255.255.255.240?

Solution

11111111 . 11111111 . 11111111 . 11110000

(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 + 2⁵ + 2⁵)

255.255.255.240

Hence there are 28 networks bits. So our answer is /28