In CIDR notation such as 192.0.2.0/24, what does the /n represent?

• A. The number of bits in the network prefix
• B. The number of hosts per subnet
• C. The total length of the address
• D. The version of IP protocol

Answer: (A)

CIDR notation uses a slash and a number to indicate how many address bits form the network prefix. In 192.0.2.0/24, 24 of the 32 bits are fixed as the network part, leaving 8 bits for hosts within that network. That’s why the /24 is the mask length, and it corresponds to a subnet mask of 255.255.255.0. The total address length in IPv4 is still 32 bits, and the version is IPv4; the /24 specifically tells you how many bits define the network portion.