Which of the following decimal to CIDR notations is not valid?

CIDR (Classless Inter-Domain Routing) notation represents the number of bits set to '1' in the subnet mask. For example, in the case of the subnet 255.255.255.0, the corresponding CIDR notation is /24, indicating that the first 24 bits of the address are used for the network part, leaving 8 bits for the host part.

The key to understanding the validity of the CIDR notations lies in the relationship between the subnet mask in decimal format and its corresponding prefix length in CIDR notation.

In this case, 255.255.255.0 corresponds to /24, as this means the first 24 bits are used for the network. The notation of 255.255.255.128 corresponds to /25, which is valid because it allows for 128 addresses in a subnet. 255.255.255.192 corresponds to /26, which is also valid, as it indicates a subnet size allowing for 64 addresses.

On the other hand, the notation 255.255.255.0 to /32 is not valid because a /32 subnet mask indicates that all 32 bits are used for the network. This means that there are no