Before the eighties, computers were large and bulky. IBM and a couple of companies were leading the way towards a smaller PC and mainframes. Intel (which started in the mid-sixties) was starting their own revolution which was making a difference in the burgeoning computer environment.
Microsoft and Apple were not yet there, but the biggest thing is that there was no internet. Not like we know it today. No IP Addresses as well.
In the seventies, there was a beginning to networking and the IP Addresses. IP Addresses were created as the original Internet routing scheme during this period. The IEEE (The Institute of Electrical and Electronic Engineers) was instrumental in the creation of the five (5) IP Classes.
As a matter of fact, these classes weren’t created to meet the needs of an ever expanding Internet. When the IEEE proposed these classes, each of the 5 classes was designed for a specific purpose.
For example, Class A (0000) was designed to meet the needs of large networks. This is the reason why this class will only support 126 networks. But each network can support 16,777,214 hosts. Class B (1000) was designed for medium-sized networks. This class will support 16,384 networks and is limited to 65,534 hosts per network.
Class C (1100) supports 2,097,152 networks but only 254 hosts per network.
In the eighties, things started to happen. Network classes were introduced more, but subnet masks were not available as yet. It wasn’t until the nineties that subnet masks appeared after the explosion of the internet and computer scientists started to realize that many of the IPv4 addresses that they (scientists) thought would be around for quite some time were running out. And that’s when subnet masking came about. To save IPv4 or should I say extend it for a little while longer. That’s when the concept and realization of IPv6 also came about.
All Class A