A subnet mask of 255.255.255.252 is equivalent to which CIDR notation?

A subnet mask of 255.255.255.252 corresponds to the CIDR notation of /30 because it represents a total of 30 bits used for the network portion of the address.

To understand this, it's important to break down the subnet mask into its binary form. The decimal value 255 translates into binary as 11111111, which indicates that all 8 bits are used for the network. The number 252 in binary is 11111100, meaning that the first 6 bits are utilized for the network, and 2 bits are left for host addresses.

When we add up the bits in the subnet mask, we find that 8 (from the first octet) + 8 (from the second octet) + 8 (from the third octet) + 6 (from the fourth octet) totals 30 bits. This gives us the CIDR notation of /30.

In practical terms, a /30 subnet allows for 4 IP addresses per subnet, out of which 2 can be assigned to hosts. This is suitable for point-to-point links where only two devices need to communicate, making it a common choice in routing scenarios.