Subnetting Questions 34 | Find the Subnet Mask from a CIDR Value

Subnetting Questions 34

What is the Subnet Mask corresponding to a shorthand of /25?

Solution

/25 indicates there are 25 network bits.

11111111.11111111.11111111.10000000

(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)

Therefore, the subnet mask is 255.255.255.128