What is the 1st Octet value range for a Class A IP Address?

The first octet value range for a Class A IP Address is 1 to 127. Class A addresses are defined for large networks and start with a first octet ranging from 1 to 126. The total number of possible Class A addresses is thus defined by this range, as the values below 1 and above 126 are reserved for special purposes (0 is reserved for the network itself, and 127 is reserved for loopback addresses).

Class A addresses are characterized by their significant number of host IPs within a network. This classification allows for potentially millions of hosts per network, making it suitable for very large organizations. This understanding of Class A addresses is essential for network design and management.

The other ranges provided in the options pertain to Class B, Class C, and Class D IP addresses. Class B covers the range 128-191, designed for medium-sized networks, Class C spans 192-223, meant for small networks, and Class D, which lies in the 224-239 range, is reserved for multicast addresses. Understanding these classifications helps network professionals design and manage IP addressing schemes effectively.