In IPv4 there are 5 different IP address classes, Class A,B,C,D,E. Keep in mind that when figuring out number of hosts, we always subtract 2, all 0’s for network and all 1’s for broadcast. Class A – 0 to 127. 2^8 networks, 2^24-2 hosts….
I am a Linux Site Reliability Engineering leader (SRE), with a focus on cloud platforms, virtualization, automation, and a wide range of other Unix infrastructure tools. You can reach me at firstname.lastname@example.org.