Which class of IP address has the most host addresses available by default?

Class A IP addresses are designed to accommodate a very large number of hosts within a single network. The Class A range starts from 1.0.0.0 to 126.255.255.255, allowing for approximately 16 million host addresses (specifically, 16,777,214 usable addresses when accounting for network and broadcast addresses). This is because Class A utilizes a subnet mask of 255.0.0.0, which allocates one octet for the network address and the remaining three octets for host addresses.

In contrast, Class B and Class C addresses provide fewer host addresses. Class B supports up to about 65,534 hosts, and Class C only allows for 254 hosts due to stricter subnetting. Therefore, Class A stands out as having the most available addresses for hosts by default, making it particularly suitable for very large organizations or networks that require extensive addressing capabilities.