Using a range of 1-126 in the first octet of an IPv4 address, what class does it belong to?

The range of 1-126 in the first octet of an IPv4 address signifies that it belongs to Class A. Class A addresses are defined for large networks, where the most significant bit (MSB) of the first octet is set to 0. This allows for a total of 128 addresses in the first octet (0-127), but since 0.0.0.0 is reserved for the default route and 127.0.0.0 is reserved for loopback purposes, the usable range for Class A is effectively 1-126.

Class A addresses support a very large number of hosts, with a default subnet mask of 255.0.0.0, meaning that the first octet identifies the network and the remaining three octets are available for host addresses within that network. This structure makes Class A suitable for very large organizations or entities that require a substantial number of IP addresses.

For context, Class B covers the range from 128 to 191, Class C spans from 192 to 223, and Class D is designated for multicast groups, with the range starting from 224 to 239. Hence, the selection of Class A is appropriate for the given range of 1