Final answer:
The range for a Class A network block is 0.0.0.0 to 127.255.255.255. These networks support extremely large networks with more than 16 million potential host addresses per network, excluding special addresses used for default routing and loopback tests.
Step-by-step explanation:
The range for a Class A network block is 1) 0.0.0.0 to 127.255.255.255. Class A networks are designed to support extremely large networks with more than 16 million host addresses available.
The first octet of a Class A IP address ranges from 0 to 127, with the first bit of the first octet being set to 0. This means that the first octet can take values from 1 to 126 for public addresses, as the addresses 0.0.0.0 and 127.0.0.0 are reserved for a special purpose (0.0.0.0 is used for default routing and 127.0.0.0 is used for loopback tests). Each Class A network supports up to 16,777,214 (2^24 - 2) hosts per network because the last octet cannot be all zeros (network address) or all ones (broadcast address).